<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2022 Workiva-->
<!--r:058207fd-5002-4d94-a410-88ebb29dc4b4,g:6d904077-cb72-434b-8ee5-0c28255b5905-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.amkor.com/role/ConsolidatedStatementsofStockholdersEquity" xlink:type="simple" xlink:href="amkr-20211231.xsd#ConsolidatedStatementsofStockholdersEquity"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/ConsolidatedStatementsofStockholdersEquity" xlink:type="extended" id="idf3f1fe0d53145579006e5b212b7e9ad_ConsolidatedStatementsofStockholdersEquity">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_961554e3-8ede-4e27-9e7e-e837af5a3c71" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_961554e3-8ede-4e27-9e7e-e837af5a3c71" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_b3c52ccd-cdaa-4a00-b984-c527355d1d7e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_CommonStockSharesIssued_b3c52ccd-cdaa-4a00-b984-c527355d1d7e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockShares_cdb233d4-beb9-409b-be5a-6c149f314311" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_TreasuryStockShares_cdb233d4-beb9-409b-be5a-6c149f314311" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_c1a104e3-9310-4464-8a78-303387020ea5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_c1a104e3-9310-4464-8a78-303387020ea5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_f5e2880a-d4af-405b-86b3-4808f72b38b5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_ProfitLoss_f5e2880a-d4af-405b-86b3-4808f72b38b5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_8e029c8f-5434-48da-aaaa-64ae240ab391" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_8e029c8f-5434-48da-aaaa-64ae240ab391" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_35d5558d-216b-4488-a6a7-804884eaad44" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_35d5558d-216b-4488-a6a7-804884eaad44" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_bc37fd8f-2b3d-4066-9147-36b555d978d3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_bc37fd8f-2b3d-4066-9147-36b555d978d3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_dfb07a73-9dcb-4174-bc34-2b7e10638942" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_dfb07a73-9dcb-4174-bc34-2b7e10638942" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_bff5d9b1-0d0a-452f-abdb-fb8330a0611f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_bff5d9b1-0d0a-452f-abdb-fb8330a0611f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_6224c12e-4054-4a00-b3cc-dac49d474bed" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_6224c12e-4054-4a00-b3cc-dac49d474bed" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCash_26586cff-e165-4bdb-86db-b2dff6af768e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DividendsCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_DividendsCash_26586cff-e165-4bdb-86db-b2dff6af768e" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_9d6e69b2-443d-4519-9ab8-598588bcb83f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_a72e8e74-e127-460c-aab1-85ef97da533b" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_9d6e69b2-443d-4519-9ab8-598588bcb83f" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_c9c36998-dc6d-4ee9-ba76-85f338c27ecd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockShares_b40d830c-9c79-4dfc-a421-7ab5dce3caf5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockShares"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_31152901-d137-4bfd-87cf-bab317d32156" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_961818a5-4f86-4233-9f49-01bdb548183c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_961554e3-8ede-4e27-9e7e-e837af5a3c71" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_961818a5-4f86-4233-9f49-01bdb548183c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_be20500b-7e00-491d-93d3-9600631970f6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_961554e3-8ede-4e27-9e7e-e837af5a3c71" xlink:to="loc_us-gaap_StatementTable_be20500b-7e00-491d-93d3-9600631970f6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_19527db8-bec5-469c-a88d-52156270e8f3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_be20500b-7e00-491d-93d3-9600631970f6" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_19527db8-bec5-469c-a88d-52156270e8f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_19527db8-bec5-469c-a88d-52156270e8f3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_19527db8-bec5-469c-a88d-52156270e8f3" xlink:to="loc_us-gaap_EquityComponentDomain_19527db8-bec5-469c-a88d-52156270e8f3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_4b40116c-f31e-401e-a43e-ed61f7bd5ed2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_19527db8-bec5-469c-a88d-52156270e8f3" xlink:to="loc_us-gaap_EquityComponentDomain_4b40116c-f31e-401e-a43e-ed61f7bd5ed2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_1f857c41-7fa2-490a-8730-713d35445d28" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4b40116c-f31e-401e-a43e-ed61f7bd5ed2" xlink:to="loc_us-gaap_ParentMember_1f857c41-7fa2-490a-8730-713d35445d28" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_7390beb1-a8cf-4b75-9302-dd2d5ae49ef5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_1f857c41-7fa2-490a-8730-713d35445d28" xlink:to="loc_us-gaap_CommonStockMember_7390beb1-a8cf-4b75-9302-dd2d5ae49ef5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_194ac289-cc95-49c1-986c-fc2e97f16edc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_1f857c41-7fa2-490a-8730-713d35445d28" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_194ac289-cc95-49c1-986c-fc2e97f16edc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_162b83b6-f239-4842-b361-1cd3ea65396c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_1f857c41-7fa2-490a-8730-713d35445d28" xlink:to="loc_us-gaap_RetainedEarningsMember_162b83b6-f239-4842-b361-1cd3ea65396c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_82057d18-723b-4e89-a592-ee8e8bc10667" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_1f857c41-7fa2-490a-8730-713d35445d28" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_82057d18-723b-4e89-a592-ee8e8bc10667" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockMember_31986422-1db4-482f-aa60-b13e850260de" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_1f857c41-7fa2-490a-8730-713d35445d28" xlink:to="loc_us-gaap_TreasuryStockMember_31986422-1db4-482f-aa60-b13e850260de" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_d3105e25-5f71-4c90-90a7-c5f28946da57" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4b40116c-f31e-401e-a43e-ed61f7bd5ed2" xlink:to="loc_us-gaap_NoncontrollingInterestMember_d3105e25-5f71-4c90-90a7-c5f28946da57" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesVariableInterestEntityDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#DescriptionofBusinessandSummaryofSignificantAccountingPoliciesVariableInterestEntityDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesVariableInterestEntityDetails" xlink:type="extended" id="id7167eb951c7472ea6c2f40fd931caf9_DescriptionofBusinessandSummaryofSignificantAccountingPoliciesVariableInterestEntityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_facc4995-678c-4085-a267-ecf4bb60f53f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityOwnershipPercentage_ef519238-c19b-4073-b157-ea0e75814de0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableInterestEntityOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_facc4995-678c-4085-a267-ecf4bb60f53f" xlink:to="loc_us-gaap_VariableInterestEntityOwnershipPercentage_ef519238-c19b-4073-b157-ea0e75814de0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_33ea4e6b-b2ce-4081-ab0e-fe94b3d77c7b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_facc4995-678c-4085-a267-ecf4bb60f53f" xlink:to="loc_us-gaap_Assets_33ea4e6b-b2ce-4081-ab0e-fe94b3d77c7b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_4d751ec4-27d4-434d-9412-1dd96308205d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_facc4995-678c-4085-a267-ecf4bb60f53f" xlink:to="loc_us-gaap_Liabilities_4d751ec4-27d4-434d-9412-1dd96308205d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_08e8d024-129b-4edb-9119-609eb87add05" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_facc4995-678c-4085-a267-ecf4bb60f53f" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_08e8d024-129b-4edb-9119-609eb87add05" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_0380a705-5bb3-42ab-b088-da57b77e90fc" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_08e8d024-129b-4edb-9119-609eb87add05" xlink:to="loc_srt_ConsolidatedEntitiesAxis_0380a705-5bb3-42ab-b088-da57b77e90fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_0380a705-5bb3-42ab-b088-da57b77e90fc_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_0380a705-5bb3-42ab-b088-da57b77e90fc" xlink:to="loc_srt_ConsolidatedEntitiesDomain_0380a705-5bb3-42ab-b088-da57b77e90fc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_2e1cf723-d401-480c-bc37-6b6df0d9722a" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_0380a705-5bb3-42ab-b088-da57b77e90fc" xlink:to="loc_srt_ConsolidatedEntitiesDomain_2e1cf723-d401-480c-bc37-6b6df0d9722a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_aec85a1e-702d-4559-82b9-9bd35b4f6f56" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_2e1cf723-d401-480c-bc37-6b6df0d9722a" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_aec85a1e-702d-4559-82b9-9bd35b4f6f56" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesOtherDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#DescriptionofBusinessandSummaryofSignificantAccountingPoliciesOtherDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesOtherDetails" xlink:type="extended" id="i98defce00072464ca74c86b1c6258876_DescriptionofBusinessandSummaryofSignificantAccountingPoliciesOtherDetails">
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_15405d5e-5bd5-44b7-99f1-f181ad96b07f" xlink:href="amkr-20211231.xsd#amkr_SummaryOfSignificantAccountingPoliciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_194a96e3-7365-4e84-bd95-d914960e3f1d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_15405d5e-5bd5-44b7-99f1-f181ad96b07f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_194a96e3-7365-4e84-bd95-d914960e3f1d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnbilledReceivablesCurrent_d2f58127-dab0-40f8-98d1-3edf87fb317b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnbilledReceivablesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_15405d5e-5bd5-44b7-99f1-f181ad96b07f" xlink:to="loc_us-gaap_UnbilledReceivablesCurrent_d2f58127-dab0-40f8-98d1-3edf87fb317b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_ScheduleOfSignificantAccountingPoliciesTable_1174ef9d-974c-4406-a38c-22340fb7e224" xlink:href="amkr-20211231.xsd#amkr_ScheduleOfSignificantAccountingPoliciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_15405d5e-5bd5-44b7-99f1-f181ad96b07f" xlink:to="loc_amkr_ScheduleOfSignificantAccountingPoliciesTable_1174ef9d-974c-4406-a38c-22340fb7e224" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d61a9cf1-5e3b-414c-a252-5241dc80309a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_amkr_ScheduleOfSignificantAccountingPoliciesTable_1174ef9d-974c-4406-a38c-22340fb7e224" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d61a9cf1-5e3b-414c-a252-5241dc80309a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d61a9cf1-5e3b-414c-a252-5241dc80309a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d61a9cf1-5e3b-414c-a252-5241dc80309a" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d61a9cf1-5e3b-414c-a252-5241dc80309a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_85d53bd2-51a3-470b-9ea0-aebd89826263" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d61a9cf1-5e3b-414c-a252-5241dc80309a" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_85d53bd2-51a3-470b-9ea0-aebd89826263" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_10730574-6b70-4d90-994a-d969c857c698" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_85d53bd2-51a3-470b-9ea0-aebd89826263" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_10730574-6b70-4d90-994a-d969c857c698" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_1070d570-f468-4a3f-b789-e9f0daa5d82e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_85d53bd2-51a3-470b-9ea0-aebd89826263" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_1070d570-f468-4a3f-b789-e9f0daa5d82e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SoftwareAndComputerEquipmentMember_9a9a9328-1d76-4226-98e5-ff83399665cf" xlink:href="amkr-20211231.xsd#amkr_SoftwareAndComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_85d53bd2-51a3-470b-9ea0-aebd89826263" xlink:to="loc_amkr_SoftwareAndComputerEquipmentMember_9a9a9328-1d76-4226-98e5-ff83399665cf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_60245c83-21f8-4160-871e-5f67a0259e6a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_85d53bd2-51a3-470b-9ea0-aebd89826263" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_60245c83-21f8-4160-871e-5f67a0259e6a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_1a8dd6c0-ea73-421b-b750-65be40d2eb75" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_amkr_ScheduleOfSignificantAccountingPoliciesTable_1174ef9d-974c-4406-a38c-22340fb7e224" xlink:to="loc_srt_RangeAxis_1a8dd6c0-ea73-421b-b750-65be40d2eb75" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_1a8dd6c0-ea73-421b-b750-65be40d2eb75_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_1a8dd6c0-ea73-421b-b750-65be40d2eb75" xlink:to="loc_srt_RangeMember_1a8dd6c0-ea73-421b-b750-65be40d2eb75_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_285fbd4a-91b9-48b0-8c01-84991ade0b81" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_1a8dd6c0-ea73-421b-b750-65be40d2eb75" xlink:to="loc_srt_RangeMember_285fbd4a-91b9-48b0-8c01-84991ade0b81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_0213408e-160d-4bfa-8e45-abbb5d0eef27" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_285fbd4a-91b9-48b0-8c01-84991ade0b81" xlink:to="loc_srt_MinimumMember_0213408e-160d-4bfa-8e45-abbb5d0eef27" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_d3300b8d-4990-42b1-8e22-72cbdefd95f1" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_285fbd4a-91b9-48b0-8c01-84991ade0b81" xlink:to="loc_srt_MaximumMember_d3300b8d-4990-42b1-8e22-72cbdefd95f1" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesNarrativeDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#DescriptionofBusinessandSummaryofSignificantAccountingPoliciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesNarrativeDetails" xlink:type="extended" id="if430ff54b1804588ba7a75aa595f5b5a_DescriptionofBusinessandSummaryofSignificantAccountingPoliciesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_928cfa6e-9478-4260-b047-1f3d4da0a3e3" xlink:href="amkr-20211231.xsd#amkr_SummaryOfSignificantAccountingPoliciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_LeaseRemainingLeaseTerm_6b11d32c-28b7-4a13-b64e-4b3cde537aa2" xlink:href="amkr-20211231.xsd#amkr_LeaseRemainingLeaseTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_928cfa6e-9478-4260-b047-1f3d4da0a3e3" xlink:to="loc_amkr_LeaseRemainingLeaseTerm_6b11d32c-28b7-4a13-b64e-4b3cde537aa2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_RevenueFromContractWithCustomerPeriodofRecognition_f9976856-30fc-4932-858a-e2b5cbea1596" xlink:href="amkr-20211231.xsd#amkr_RevenueFromContractWithCustomerPeriodofRecognition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_928cfa6e-9478-4260-b047-1f3d4da0a3e3" xlink:to="loc_amkr_RevenueFromContractWithCustomerPeriodofRecognition_f9976856-30fc-4932-858a-e2b5cbea1596" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiability_521554d8-7500-48ae-a0b9-c2daa8e548e9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_928cfa6e-9478-4260-b047-1f3d4da0a3e3" xlink:to="loc_us-gaap_ContractWithCustomerLiability_521554d8-7500-48ae-a0b9-c2daa8e548e9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_52ad6531-ba5f-4e02-b484-5b51f2d68ebf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_928cfa6e-9478-4260-b047-1f3d4da0a3e3" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_52ad6531-ba5f-4e02-b484-5b51f2d68ebf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_f710409f-823a-4a7f-8b88-8ed1affa8b39" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_928cfa6e-9478-4260-b047-1f3d4da0a3e3" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_f710409f-823a-4a7f-8b88-8ed1affa8b39" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_ScheduleOfSignificantAccountingPoliciesTable_ebf62857-2e33-4ab2-a1a5-cc7719c81d1e" xlink:href="amkr-20211231.xsd#amkr_ScheduleOfSignificantAccountingPoliciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_amkr_SummaryOfSignificantAccountingPoliciesLineItems_928cfa6e-9478-4260-b047-1f3d4da0a3e3" xlink:to="loc_amkr_ScheduleOfSignificantAccountingPoliciesTable_ebf62857-2e33-4ab2-a1a5-cc7719c81d1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_fd525a89-7bd2-4947-9bbc-b631492d04ec" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_amkr_ScheduleOfSignificantAccountingPoliciesTable_ebf62857-2e33-4ab2-a1a5-cc7719c81d1e" xlink:to="loc_srt_RangeAxis_fd525a89-7bd2-4947-9bbc-b631492d04ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_fd525a89-7bd2-4947-9bbc-b631492d04ec_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_fd525a89-7bd2-4947-9bbc-b631492d04ec" xlink:to="loc_srt_RangeMember_fd525a89-7bd2-4947-9bbc-b631492d04ec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_44811f78-17f2-4c91-9447-a7ce7abd876a" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_fd525a89-7bd2-4947-9bbc-b631492d04ec" xlink:to="loc_srt_RangeMember_44811f78-17f2-4c91-9447-a7ce7abd876a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_fa276a63-a3d6-4be3-bb49-5b7f91879482" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_44811f78-17f2-4c91-9447-a7ce7abd876a" xlink:to="loc_srt_MinimumMember_fa276a63-a3d6-4be3-bb49-5b7f91879482" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_85634715-5bb0-45ac-9ac8-28beb968dc7c" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_44811f78-17f2-4c91-9447-a7ce7abd876a" xlink:to="loc_srt_MaximumMember_85634715-5bb0-45ac-9ac8-28beb968dc7c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_d678b5c9-c108-407e-b7ea-403f67d2b7a3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_amkr_ScheduleOfSignificantAccountingPoliciesTable_ebf62857-2e33-4ab2-a1a5-cc7719c81d1e" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_d678b5c9-c108-407e-b7ea-403f67d2b7a3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_d678b5c9-c108-407e-b7ea-403f67d2b7a3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_d678b5c9-c108-407e-b7ea-403f67d2b7a3" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_d678b5c9-c108-407e-b7ea-403f67d2b7a3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_0514bef6-f853-4245-a9a4-a853a4620d0b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_d678b5c9-c108-407e-b7ea-403f67d2b7a3" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_0514bef6-f853-4245-a9a4-a853a4620d0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c5323dc0-04a0-465f-9944-76c95e851d78" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_amkr_ScheduleOfSignificantAccountingPoliciesTable_ebf62857-2e33-4ab2-a1a5-cc7719c81d1e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c5323dc0-04a0-465f-9944-76c95e851d78" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c5323dc0-04a0-465f-9944-76c95e851d78_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c5323dc0-04a0-465f-9944-76c95e851d78" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c5323dc0-04a0-465f-9944-76c95e851d78_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_722ece73-0968-45ae-b3aa-74138614d8f7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c5323dc0-04a0-465f-9944-76c95e851d78" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_722ece73-0968-45ae-b3aa-74138614d8f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_c4441c40-8fbf-487d-8571-1ffc5db00f7e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_722ece73-0968-45ae-b3aa-74138614d8f7" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_c4441c40-8fbf-487d-8571-1ffc5db00f7e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_1b8b164a-5c1c-42d2-ad71-e2c95faea30f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_722ece73-0968-45ae-b3aa-74138614d8f7" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_1b8b164a-5c1c-42d2-ad71-e2c95faea30f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SoftwareAndComputerEquipmentMember_7cba5ed8-2f50-4edf-9126-d43d901a1fbd" xlink:href="amkr-20211231.xsd#amkr_SoftwareAndComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_722ece73-0968-45ae-b3aa-74138614d8f7" xlink:to="loc_amkr_SoftwareAndComputerEquipmentMember_7cba5ed8-2f50-4edf-9126-d43d901a1fbd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_90cdbc41-4be1-4d18-8e12-e9b034c8c5de" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_722ece73-0968-45ae-b3aa-74138614d8f7" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_90cdbc41-4be1-4d18-8e12-e9b034c8c5de" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesPerformanceObligationDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#DescriptionofBusinessandSummaryofSignificantAccountingPoliciesPerformanceObligationDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesPerformanceObligationDetails" xlink:type="extended" id="i8a453f9fa8e14b07a2e56c17ed788d43_DescriptionofBusinessandSummaryofSignificantAccountingPoliciesPerformanceObligationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_665b0e4f-731c-426b-8586-c6864f5e1bf1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_2d9fcaae-1b43-4632-a41a-a57f14beb7b9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_665b0e4f-731c-426b-8586-c6864f5e1bf1" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_2d9fcaae-1b43-4632-a41a-a57f14beb7b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_f15ece6f-4f13-4d40-9aaa-95664e317b05" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_665b0e4f-731c-426b-8586-c6864f5e1bf1" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_f15ece6f-4f13-4d40-9aaa-95664e317b05" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_7aa7691a-9863-4857-9e12-fb4fef46ae3f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_f15ece6f-4f13-4d40-9aaa-95664e317b05" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_7aa7691a-9863-4857-9e12-fb4fef46ae3f" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesPerformanceObligationDetails_1" xlink:type="simple" xlink:href="amkr-20211231.xsd#DescriptionofBusinessandSummaryofSignificantAccountingPoliciesPerformanceObligationDetails_1"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesPerformanceObligationDetails_1" xlink:type="extended" id="i2b7340f2ee284fe386b08b96ef42b63d_DescriptionofBusinessandSummaryofSignificantAccountingPoliciesPerformanceObligationDetails_1">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_665b0e4f-731c-426b-8586-c6864f5e1bf1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_2d9fcaae-1b43-4632-a41a-a57f14beb7b9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_665b0e4f-731c-426b-8586-c6864f5e1bf1" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_2d9fcaae-1b43-4632-a41a-a57f14beb7b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_f15ece6f-4f13-4d40-9aaa-95664e317b05" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_665b0e4f-731c-426b-8586-c6864f5e1bf1" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_f15ece6f-4f13-4d40-9aaa-95664e317b05" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/ShareBasedCompensationPlansRestrictedSharesDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#ShareBasedCompensationPlansRestrictedSharesDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/ShareBasedCompensationPlansRestrictedSharesDetails" xlink:type="extended" id="idce7eb67eab6451181ddf79d4683d69c_ShareBasedCompensationPlansRestrictedSharesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b0632a71-8c08-4514-9f14-14f862178d02" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cd41951-76cb-4e32-bff9-1810ca3d62d9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b0632a71-8c08-4514-9f14-14f862178d02" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cd41951-76cb-4e32-bff9-1810ca3d62d9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_08bb9ee9-16d2-40ff-9ff4-462b416f5558" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cd41951-76cb-4e32-bff9-1810ca3d62d9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_08bb9ee9-16d2-40ff-9ff4-462b416f5558" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_10dd85ca-e92b-4fb9-b12f-9df8bc93c569" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cd41951-76cb-4e32-bff9-1810ca3d62d9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_10dd85ca-e92b-4fb9-b12f-9df8bc93c569" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_5c668a0b-cdd1-46f1-ac54-86935e916227" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cd41951-76cb-4e32-bff9-1810ca3d62d9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_5c668a0b-cdd1-46f1-ac54-86935e916227" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_daf47a20-b157-4b08-ada7-03fa2c205d08" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cd41951-76cb-4e32-bff9-1810ca3d62d9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_daf47a20-b157-4b08-ada7-03fa2c205d08" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_6a8df6b4-18a0-4407-b33f-32e485f5f137" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_ef09713f-3748-499b-a04c-64fc4c3d53fd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b0632a71-8c08-4514-9f14-14f862178d02" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_ef09713f-3748-499b-a04c-64fc4c3d53fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_0c8e79fb-7a95-4211-80ed-64bdaf3e9ed0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_ef09713f-3748-499b-a04c-64fc4c3d53fd" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_0c8e79fb-7a95-4211-80ed-64bdaf3e9ed0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_fa295c6d-68f0-4b45-a5fd-e4e785326ca1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_ef09713f-3748-499b-a04c-64fc4c3d53fd" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_fa295c6d-68f0-4b45-a5fd-e4e785326ca1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_e387a015-0e6a-4d04-9ff3-dde2c8cbcd68" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_ef09713f-3748-499b-a04c-64fc4c3d53fd" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_e387a015-0e6a-4d04-9ff3-dde2c8cbcd68" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_f974595a-ddd2-460c-aeb9-1ed4af5f33c9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_ef09713f-3748-499b-a04c-64fc4c3d53fd" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_f974595a-ddd2-460c-aeb9-1ed4af5f33c9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_95566a95-6858-4e79-846e-89345f5242d9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_ff0a675c-de41-4511-b06a-5c792dbe2e6b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b0632a71-8c08-4514-9f14-14f862178d02" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_ff0a675c-de41-4511-b06a-5c792dbe2e6b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_e002f72e-7642-45d9-8fa9-891d2bfe6d17" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_ff0a675c-de41-4511-b06a-5c792dbe2e6b" xlink:to="loc_us-gaap_AwardTypeAxis_e002f72e-7642-45d9-8fa9-891d2bfe6d17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e002f72e-7642-45d9-8fa9-891d2bfe6d17_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_e002f72e-7642-45d9-8fa9-891d2bfe6d17" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e002f72e-7642-45d9-8fa9-891d2bfe6d17_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cd2be2f6-dbf9-44ff-88f6-41c983c414c9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_e002f72e-7642-45d9-8fa9-891d2bfe6d17" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cd2be2f6-dbf9-44ff-88f6-41c983c414c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_e699bc9b-98e5-4a33-b901-c4e6e18d9ea9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cd2be2f6-dbf9-44ff-88f6-41c983c414c9" xlink:to="loc_us-gaap_RestrictedStockMember_e699bc9b-98e5-4a33-b901-c4e6e18d9ea9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_ba0db552-2231-405b-bea1-c668edfaaed9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cd2be2f6-dbf9-44ff-88f6-41c983c414c9" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_ba0db552-2231-405b-bea1-c668edfaaed9" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/ShareBasedCompensationPlansNarrativeDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#ShareBasedCompensationPlansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/ShareBasedCompensationPlansNarrativeDetails" xlink:type="extended" id="i3852f7c676a34a6d9d7fe28f51a6c758_ShareBasedCompensationPlansNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_86cf1d8d-53c2-414e-b81f-b7f44bc5fc1a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_86cf1d8d-53c2-414e-b81f-b7f44bc5fc1a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_5b1bfcf9-6075-46d4-8d4c-5ddd5cf15f57" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_5b1bfcf9-6075-46d4-8d4c-5ddd5cf15f57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_437066e8-8a3b-4557-9569-6ee3cfda515d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_437066e8-8a3b-4557-9569-6ee3cfda515d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_17133e66-a4f4-4bf3-a9cc-b1bfd085c1d4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_17133e66-a4f4-4bf3-a9cc-b1bfd085c1d4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_89968565-82c0-4ddd-8dac-386a923e2213" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_89968565-82c0-4ddd-8dac-386a923e2213" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_79a65e79-c7e3-497e-82ea-77e2b6c113c1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_79a65e79-c7e3-497e-82ea-77e2b6c113c1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_58ed8d20-f3e5-4537-8549-df6c7b460d55" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_58ed8d20-f3e5-4537-8549-df6c7b460d55" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_3febb0f6-8efd-4537-99fb-61e1bce47d31" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_3febb0f6-8efd-4537-99fb-61e1bce47d31" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_64c37db9-97c4-46f7-b05a-313c9637abd1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_64c37db9-97c4-46f7-b05a-313c9637abd1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_2bfd829d-6e36-4881-8315-b743ff972c18" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_2bfd829d-6e36-4881-8315-b743ff972c18" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_RestrictedSharesVestingPercentage_4abb8174-622e-495a-810c-26a0b2065610" xlink:href="amkr-20211231.xsd#amkr_RestrictedSharesVestingPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_amkr_RestrictedSharesVestingPercentage_4abb8174-622e-495a-810c-26a0b2065610" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5c4e8fa9-03ee-489a-a150-9e76cd526506" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f59cc98c-98cf-4de5-9a87-4e99b612ec18" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5c4e8fa9-03ee-489a-a150-9e76cd526506" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis_840dc52d-ccb9-491f-a3e2-6f03ff29e8a3" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_TitleOfIndividualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5c4e8fa9-03ee-489a-a150-9e76cd526506" xlink:to="loc_srt_TitleOfIndividualAxis_840dc52d-ccb9-491f-a3e2-6f03ff29e8a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_840dc52d-ccb9-491f-a3e2-6f03ff29e8a3_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_840dc52d-ccb9-491f-a3e2-6f03ff29e8a3" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_840dc52d-ccb9-491f-a3e2-6f03ff29e8a3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_a94f2793-ae27-41dd-81c2-b736a016fb2d" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_840dc52d-ccb9-491f-a3e2-6f03ff29e8a3" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_a94f2793-ae27-41dd-81c2-b736a016fb2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_DirectorMember_61a44cf2-2c1d-489b-85db-47f36de3bb4c" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_DirectorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_a94f2793-ae27-41dd-81c2-b736a016fb2d" xlink:to="loc_srt_DirectorMember_61a44cf2-2c1d-489b-85db-47f36de3bb4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_6fc63e61-9d29-46bd-87b5-0f584791c5e4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5c4e8fa9-03ee-489a-a150-9e76cd526506" xlink:to="loc_us-gaap_AwardTypeAxis_6fc63e61-9d29-46bd-87b5-0f584791c5e4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6fc63e61-9d29-46bd-87b5-0f584791c5e4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_6fc63e61-9d29-46bd-87b5-0f584791c5e4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6fc63e61-9d29-46bd-87b5-0f584791c5e4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_81ae9aca-ff59-4aef-bd67-35ea114265b4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_6fc63e61-9d29-46bd-87b5-0f584791c5e4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_81ae9aca-ff59-4aef-bd67-35ea114265b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_a1c9290e-38f7-4407-b11a-ed6b719cd03e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_81ae9aca-ff59-4aef-bd67-35ea114265b4" xlink:to="loc_us-gaap_EmployeeStockOptionMember_a1c9290e-38f7-4407-b11a-ed6b719cd03e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_cf4ec9d2-0d38-4c12-8768-13e1cf46a456" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_81ae9aca-ff59-4aef-bd67-35ea114265b4" xlink:to="loc_us-gaap_RestrictedStockMember_cf4ec9d2-0d38-4c12-8768-13e1cf46a456" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_5710cf10-1002-4abe-9e9b-94ad35a267e6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_81ae9aca-ff59-4aef-bd67-35ea114265b4" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_5710cf10-1002-4abe-9e9b-94ad35a267e6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_b214eda9-5fde-4129-8ead-a3b066b13a6f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5c4e8fa9-03ee-489a-a150-9e76cd526506" xlink:to="loc_us-gaap_PlanNameAxis_b214eda9-5fde-4129-8ead-a3b066b13a6f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_b214eda9-5fde-4129-8ead-a3b066b13a6f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_b214eda9-5fde-4129-8ead-a3b066b13a6f" xlink:to="loc_us-gaap_PlanNameDomain_b214eda9-5fde-4129-8ead-a3b066b13a6f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_ae25ba8b-1834-4a4d-b81d-ba0b9f4a5790" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_b214eda9-5fde-4129-8ead-a3b066b13a6f" xlink:to="loc_us-gaap_PlanNameDomain_ae25ba8b-1834-4a4d-b81d-ba0b9f4a5790" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TwoThousandSevenEquityIncentivePlanMember_69ae0230-9eed-4024-96a4-1641cb8f4967" xlink:href="amkr-20211231.xsd#amkr_TwoThousandSevenEquityIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_ae25ba8b-1834-4a4d-b81d-ba0b9f4a5790" xlink:to="loc_amkr_TwoThousandSevenEquityIncentivePlanMember_69ae0230-9eed-4024-96a4-1641cb8f4967" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TwoThousandTwentyOneEquityIncentivePlanMemberMember_7e715401-61cf-426e-b49c-d9058d10fa50" xlink:href="amkr-20211231.xsd#amkr_TwoThousandTwentyOneEquityIncentivePlanMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_ae25ba8b-1834-4a4d-b81d-ba0b9f4a5790" xlink:to="loc_amkr_TwoThousandTwentyOneEquityIncentivePlanMemberMember_7e715401-61cf-426e-b49c-d9058d10fa50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_600ae49e-9553-4aec-9e6d-63b992e0f7d0" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5c4e8fa9-03ee-489a-a150-9e76cd526506" xlink:to="loc_srt_RangeAxis_600ae49e-9553-4aec-9e6d-63b992e0f7d0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_600ae49e-9553-4aec-9e6d-63b992e0f7d0_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_600ae49e-9553-4aec-9e6d-63b992e0f7d0" xlink:to="loc_srt_RangeMember_600ae49e-9553-4aec-9e6d-63b992e0f7d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_ca0ff036-6b03-4b6d-b83e-16eb7a8e48ed" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_600ae49e-9553-4aec-9e6d-63b992e0f7d0" xlink:to="loc_srt_RangeMember_ca0ff036-6b03-4b6d-b83e-16eb7a8e48ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_7bc98dcf-721b-41ea-8744-78b09e71ee23" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ca0ff036-6b03-4b6d-b83e-16eb7a8e48ed" xlink:to="loc_srt_MinimumMember_7bc98dcf-721b-41ea-8744-78b09e71ee23" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_440d3697-3add-45b7-81ad-9e2d033006c2" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ca0ff036-6b03-4b6d-b83e-16eb7a8e48ed" xlink:to="loc_srt_MaximumMember_440d3697-3add-45b7-81ad-9e2d033006c2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/IncomeTaxesValuationallowanceDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#IncomeTaxesValuationallowanceDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/IncomeTaxesValuationallowanceDetails" xlink:type="extended" id="i80a74e67d4464324a9c3a4c2ac5b6503_IncomeTaxesValuationallowanceDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceLineItems_ba43bb22-e6b5-4998-9bc4-d0c3de86e32d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowanceLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_cef80039-1a59-4d77-9d00-6a9fcf2dcdcb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowanceLineItems_ba43bb22-e6b5-4998-9bc4-d0c3de86e32d" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_cef80039-1a59-4d77-9d00-6a9fcf2dcdcb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceTable_a322888e-ce44-46d3-96f6-2ee285ed8bdd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowanceTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ValuationAllowanceLineItems_ba43bb22-e6b5-4998-9bc4-d0c3de86e32d" xlink:to="loc_us-gaap_ValuationAllowanceTable_a322888e-ce44-46d3-96f6-2ee285ed8bdd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_b3f604ed-c20a-4620-8ca5-25e6f1b1262e" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ValuationAllowanceTable_a322888e-ce44-46d3-96f6-2ee285ed8bdd" xlink:to="loc_srt_StatementGeographicalAxis_b3f604ed-c20a-4620-8ca5-25e6f1b1262e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_b3f604ed-c20a-4620-8ca5-25e6f1b1262e_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_b3f604ed-c20a-4620-8ca5-25e6f1b1262e" xlink:to="loc_srt_SegmentGeographicalDomain_b3f604ed-c20a-4620-8ca5-25e6f1b1262e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_dfe48954-82c6-429f-b78f-18444d940dd1" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_b3f604ed-c20a-4620-8ca5-25e6f1b1262e" xlink:to="loc_srt_SegmentGeographicalDomain_dfe48954-82c6-429f-b78f-18444d940dd1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_957178e6-7893-4888-883a-376482c01d4a" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_dfe48954-82c6-429f-b78f-18444d940dd1" xlink:to="loc_country_US_957178e6-7893-4888-883a-376482c01d4a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_PT_0f1ccd97-8fe3-4325-b24e-07dc1dc7d653" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_PT"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_dfe48954-82c6-429f-b78f-18444d940dd1" xlink:to="loc_country_PT_0f1ccd97-8fe3-4325-b24e-07dc1dc7d653" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/IncomeTaxesNetoperatinglosscarryforwardsDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#IncomeTaxesNetoperatinglosscarryforwardsDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/IncomeTaxesNetoperatinglosscarryforwardsDetails" xlink:type="extended" id="iac34b33d2b114c26b39764e228aacb77_IncomeTaxesNetoperatinglosscarryforwardsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsLineItems_1b22b7e9-b896-4611-821b-b2b3c776f67d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLossCarryforwardsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_IncomeTaxesTextualsAbstract_12590ae0-9389-4101-8735-f06c2438f35e" xlink:href="amkr-20211231.xsd#amkr_IncomeTaxesTextualsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_1b22b7e9-b896-4611-821b-b2b3c776f67d" xlink:to="loc_amkr_IncomeTaxesTextualsAbstract_12590ae0-9389-4101-8735-f06c2438f35e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwards_6af1da19-15c2-412c-9165-06a1dfad36cb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLossCarryforwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_IncomeTaxesTextualsAbstract_12590ae0-9389-4101-8735-f06c2438f35e" xlink:to="loc_us-gaap_OperatingLossCarryforwards_6af1da19-15c2-412c-9165-06a1dfad36cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsTable_e7899825-ac07-4031-ae85-c4125bc95289" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLossCarryforwardsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_1b22b7e9-b896-4611-821b-b2b3c776f67d" xlink:to="loc_us-gaap_OperatingLossCarryforwardsTable_e7899825-ac07-4031-ae85-c4125bc95289" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_943bcb8c-5f1b-430e-96dd-64bde5c9cbc8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_e7899825-ac07-4031-ae85-c4125bc95289" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_943bcb8c-5f1b-430e-96dd-64bde5c9cbc8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_943bcb8c-5f1b-430e-96dd-64bde5c9cbc8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_943bcb8c-5f1b-430e-96dd-64bde5c9cbc8" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_943bcb8c-5f1b-430e-96dd-64bde5c9cbc8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_3b5e09e3-6b79-4818-a36c-fb4da1fb3813" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_943bcb8c-5f1b-430e-96dd-64bde5c9cbc8" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_3b5e09e3-6b79-4818-a36c-fb4da1fb3813" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalRevenueServiceIRSMember_04a9c3fd-87d6-4b4c-aa45-94c65dc35348" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InternalRevenueServiceIRSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_3b5e09e3-6b79-4818-a36c-fb4da1fb3813" xlink:to="loc_us-gaap_InternalRevenueServiceIRSMember_04a9c3fd-87d6-4b4c-aa45-94c65dc35348" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember_733e715a-613b-4e27-b0c0-9c53bf40de29" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StateAndLocalJurisdictionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_3b5e09e3-6b79-4818-a36c-fb4da1fb3813" xlink:to="loc_us-gaap_StateAndLocalJurisdictionMember_733e715a-613b-4e27-b0c0-9c53bf40de29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_fe390db5-ee44-44a9-a011-421ebb31ba1d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_3b5e09e3-6b79-4818-a36c-fb4da1fb3813" xlink:to="loc_us-gaap_NonUsMember_fe390db5-ee44-44a9-a011-421ebb31ba1d" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/IncomeTaxesTaxcreditcarryforwardsDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#IncomeTaxesTaxcreditcarryforwardsDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/IncomeTaxesTaxcreditcarryforwardsDetails" xlink:type="extended" id="i0b55c5f5cdf74b6c92ca243cdf2784fb_IncomeTaxesTaxcreditcarryforwardsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardLineItems_47489c25-e14d-4e01-a274-946aab229666" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TaxCreditCarryforwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardAmount_983ef8ff-8d52-450f-8ebc-ea5624d779b6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TaxCreditCarryforwardAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_47489c25-e14d-4e01-a274-946aab229666" xlink:to="loc_us-gaap_TaxCreditCarryforwardAmount_983ef8ff-8d52-450f-8ebc-ea5624d779b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardTable_bbccad31-12be-44a9-99cb-fc1773f436eb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TaxCreditCarryforwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_TaxCreditCarryforwardLineItems_47489c25-e14d-4e01-a274-946aab229666" xlink:to="loc_us-gaap_TaxCreditCarryforwardTable_bbccad31-12be-44a9-99cb-fc1773f436eb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_b555d27a-bb01-4271-ab65-182e91d4f1f7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TaxCreditCarryforwardTable_bbccad31-12be-44a9-99cb-fc1773f436eb" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_b555d27a-bb01-4271-ab65-182e91d4f1f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_b555d27a-bb01-4271-ab65-182e91d4f1f7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_b555d27a-bb01-4271-ab65-182e91d4f1f7" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_b555d27a-bb01-4271-ab65-182e91d4f1f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_4948baad-043a-4b71-a3dc-ae8c1e76884c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_b555d27a-bb01-4271-ab65-182e91d4f1f7" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_4948baad-043a-4b71-a3dc-ae8c1e76884c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember_abe08f86-5e05-45d0-a881-0fcb34cc053f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_4948baad-043a-4b71-a3dc-ae8c1e76884c" xlink:to="loc_us-gaap_DomesticCountryMember_abe08f86-5e05-45d0-a881-0fcb34cc053f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_3c606238-4895-4b26-849f-f4d572549ce7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_4948baad-043a-4b71-a3dc-ae8c1e76884c" xlink:to="loc_us-gaap_ForeignCountryMember_3c606238-4895-4b26-849f-f4d572549ce7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardAxis_d75031e0-c367-4c2e-bce1-1a7fd9cfbbe9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TaxCreditCarryforwardAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TaxCreditCarryforwardTable_bbccad31-12be-44a9-99cb-fc1773f436eb" xlink:to="loc_us-gaap_TaxCreditCarryforwardAxis_d75031e0-c367-4c2e-bce1-1a7fd9cfbbe9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardNameDomain_d75031e0-c367-4c2e-bce1-1a7fd9cfbbe9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TaxCreditCarryforwardNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TaxCreditCarryforwardAxis_d75031e0-c367-4c2e-bce1-1a7fd9cfbbe9" xlink:to="loc_us-gaap_TaxCreditCarryforwardNameDomain_d75031e0-c367-4c2e-bce1-1a7fd9cfbbe9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardNameDomain_49ff3e3e-f908-471a-84cd-34d1ac4adcb2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TaxCreditCarryforwardNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TaxCreditCarryforwardAxis_d75031e0-c367-4c2e-bce1-1a7fd9cfbbe9" xlink:to="loc_us-gaap_TaxCreditCarryforwardNameDomain_49ff3e3e-f908-471a-84cd-34d1ac4adcb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_ForeignTaxCreditCarryforwardMember_ece80d41-c1f7-4f36-8342-3a959ffa857b" xlink:href="amkr-20211231.xsd#amkr_ForeignTaxCreditCarryforwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardNameDomain_49ff3e3e-f908-471a-84cd-34d1ac4adcb2" xlink:to="loc_amkr_ForeignTaxCreditCarryforwardMember_ece80d41-c1f7-4f36-8342-3a959ffa857b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_OtherTaxCreditCarryforwardMember_95c6584c-6217-4db7-939f-f7161f4304cf" xlink:href="amkr-20211231.xsd#amkr_OtherTaxCreditCarryforwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardNameDomain_49ff3e3e-f908-471a-84cd-34d1ac4adcb2" xlink:to="loc_amkr_OtherTaxCreditCarryforwardMember_95c6584c-6217-4db7-939f-f7161f4304cf" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/InvestmentsSummaryofShorttermInvestmentsDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#InvestmentsSummaryofShorttermInvestmentsDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/InvestmentsSummaryofShorttermInvestmentsDetails" xlink:type="extended" id="i70c5d70f8aa4471eb892055db67aa027_InvestmentsSummaryofShorttermInvestmentsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_41e30254-10c0-4f15-8537-66c31e8d7d41" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_41e30254-10c0-4f15-8537-66c31e8d7d41" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_9363f4e2-eff9-40ed-bc38-a417a0eb781a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_9363f4e2-eff9-40ed-bc38-a417a0eb781a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_d72db094-214c-4f1a-817a-d10ae99c6734" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_d72db094-214c-4f1a-817a-d10ae99c6734" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_bc4cf0d7-a2b9-468a-9810-c4b0af64442d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_bc4cf0d7-a2b9-468a-9810-c4b0af64442d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_CashandCashEquivalentsandDebtSecuritiesAvailableforsaleFairValueDisclosure_efacada9-8ab3-4efb-bf5b-e9e2e2ad904f" xlink:href="amkr-20211231.xsd#amkr_CashandCashEquivalentsandDebtSecuritiesAvailableforsaleFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_amkr_CashandCashEquivalentsandDebtSecuritiesAvailableforsaleFairValueDisclosure_efacada9-8ab3-4efb-bf5b-e9e2e2ad904f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_36eb0263-6359-456b-a7e7-e611964223ea" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_36eb0263-6359-456b-a7e7-e611964223ea" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_386fcf50-4a7e-462c-b97f-a502c503d96b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_386fcf50-4a7e-462c-b97f-a502c503d96b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_00215ead-341c-47bf-83b0-85d6d83ab06b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_00215ead-341c-47bf-83b0-85d6d83ab06b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_ee7d06d2-7015-4b13-b878-262b0c6fb3f0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_ee7d06d2-7015-4b13-b878-262b0c6fb3f0" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_15548c3e-a368-4326-b915-69cc3dce51bd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_15548c3e-a368-4326-b915-69cc3dce51bd" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_02eb6cc2-25f0-4bb7-a7ae-c049d14c6603" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_02eb6cc2-25f0-4bb7-a7ae-c049d14c6603" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_c1e4bdbd-f160-4e4c-9207-642a1fe17e35" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_c1e4bdbd-f160-4e4c-9207-642a1fe17e35" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_f5d13111-9940-4a37-899d-8f5ae1254996" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_f5d13111-9940-4a37-899d-8f5ae1254996" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_b5dbc739-9f2d-4f35-b1d6-3e324c5a908d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_b5dbc739-9f2d-4f35-b1d6-3e324c5a908d" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_aaf64416-9867-4858-accf-5b7900c5fa33" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesFairValue_aaf64416-9867-4858-accf-5b7900c5fa33" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_dfccd2d6-398d-4f96-aa09-41af8e8e7d16" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_ccd8b66f-8b49-4e5c-9794-8c79c7a72e4b" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_dfccd2d6-398d-4f96-aa09-41af8e8e7d16" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_476ad676-e873-4061-b33f-220a62f45cdf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_dfccd2d6-398d-4f96-aa09-41af8e8e7d16" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_476ad676-e873-4061-b33f-220a62f45cdf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_476ad676-e873-4061-b33f-220a62f45cdf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_476ad676-e873-4061-b33f-220a62f45cdf" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_476ad676-e873-4061-b33f-220a62f45cdf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ed6dabfc-5bc3-47b5-a2e7-0b668c28631d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_476ad676-e873-4061-b33f-220a62f45cdf" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ed6dabfc-5bc3-47b5-a2e7-0b668c28631d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_8858da0b-e4e9-4f9c-9bcf-6ee7cf43b93a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ed6dabfc-5bc3-47b5-a2e7-0b668c28631d" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_8858da0b-e4e9-4f9c-9bcf-6ee7cf43b93a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_9ffbb6a1-773e-4eeb-b42f-d4ea934b82f5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ed6dabfc-5bc3-47b5-a2e7-0b668c28631d" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_9ffbb6a1-773e-4eeb-b42f-d4ea934b82f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_789bb0a5-fdb1-4bf4-8c47-6adc77821091" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_dfccd2d6-398d-4f96-aa09-41af8e8e7d16" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_789bb0a5-fdb1-4bf4-8c47-6adc77821091" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_789bb0a5-fdb1-4bf4-8c47-6adc77821091_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_789bb0a5-fdb1-4bf4-8c47-6adc77821091" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_789bb0a5-fdb1-4bf4-8c47-6adc77821091_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_2aa79525-0717-4af8-b46a-691cfff31d8d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_789bb0a5-fdb1-4bf4-8c47-6adc77821091" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_2aa79525-0717-4af8-b46a-691cfff31d8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashEquivalentsMember_24298014-59ed-4925-b1b8-a7f7eb3ce96d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_2aa79525-0717-4af8-b46a-691cfff31d8d" xlink:to="loc_us-gaap_CashEquivalentsMember_24298014-59ed-4925-b1b8-a7f7eb3ce96d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CertificatesOfDepositMember_b100f3f3-4bfb-4164-8f90-fc9328df7ffa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CertificatesOfDepositMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashEquivalentsMember_24298014-59ed-4925-b1b8-a7f7eb3ce96d" xlink:to="loc_us-gaap_CertificatesOfDepositMember_b100f3f3-4bfb-4164-8f90-fc9328df7ffa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_5c099ecd-0d27-46c3-9a23-63d2703c229a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashEquivalentsMember_24298014-59ed-4925-b1b8-a7f7eb3ce96d" xlink:to="loc_us-gaap_CommercialPaperMember_5c099ecd-0d27-46c3-9a23-63d2703c229a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_678ab2f9-0ac3-4bbb-a134-b5095a58b2b9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashEquivalentsMember_24298014-59ed-4925-b1b8-a7f7eb3ce96d" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_678ab2f9-0ac3-4bbb-a134-b5095a58b2b9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_42dc41a7-859d-4139-897a-2a1376a29948" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashEquivalentsMember_24298014-59ed-4925-b1b8-a7f7eb3ce96d" xlink:to="loc_us-gaap_MoneyMarketFundsMember_42dc41a7-859d-4139-897a-2a1376a29948" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MunicipalBondsMember_cf74814f-5449-4de2-a96e-a96a70cb5b73" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MunicipalBondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashEquivalentsMember_24298014-59ed-4925-b1b8-a7f7eb3ce96d" xlink:to="loc_us-gaap_MunicipalBondsMember_cf74814f-5449-4de2-a96e-a96a70cb5b73" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_002bcef0-12f5-4ae6-a872-db29645449ae" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashEquivalentsMember_24298014-59ed-4925-b1b8-a7f7eb3ce96d" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_002bcef0-12f5-4ae6-a872-db29645449ae" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_efaf3057-3f60-47b2-8066-620270fba266" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_dfccd2d6-398d-4f96-aa09-41af8e8e7d16" xlink:to="loc_us-gaap_FinancialInstrumentAxis_efaf3057-3f60-47b2-8066-620270fba266" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_efaf3057-3f60-47b2-8066-620270fba266_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_efaf3057-3f60-47b2-8066-620270fba266" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_efaf3057-3f60-47b2-8066-620270fba266_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2c18292b-8980-4ab2-84b3-76998b73e067" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_efaf3057-3f60-47b2-8066-620270fba266" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2c18292b-8980-4ab2-84b3-76998b73e067" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShortTermInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2c18292b-8980-4ab2-84b3-76998b73e067" xlink:to="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetBackedSecuritiesMember_7f656fae-3ede-4d82-9dc8-3e00fe6d161a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:to="loc_us-gaap_AssetBackedSecuritiesMember_7f656fae-3ede-4d82-9dc8-3e00fe6d161a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CertificatesOfDepositMember_4c0ee98f-b3ca-4039-a49d-e57cb63f8efd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CertificatesOfDepositMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:to="loc_us-gaap_CertificatesOfDepositMember_4c0ee98f-b3ca-4039-a49d-e57cb63f8efd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_149ff624-0df6-4520-8418-2cf914622b86" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:to="loc_us-gaap_CommercialPaperMember_149ff624-0df6-4520-8418-2cf914622b86" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_12385e81-94ac-46c3-be92-1115c909cae9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_12385e81-94ac-46c3-be92-1115c909cae9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignGovernmentShorttermDebtSecuritiesMember_52ff438a-6c01-4245-a27c-1ef2ffe94495" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignGovernmentShorttermDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:to="loc_us-gaap_ForeignGovernmentShorttermDebtSecuritiesMember_52ff438a-6c01-4245-a27c-1ef2ffe94495" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MunicipalBondsMember_be1b65fc-db71-4dba-9b21-0356a2c3702a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MunicipalBondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:to="loc_us-gaap_MunicipalBondsMember_be1b65fc-db71-4dba-9b21-0356a2c3702a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_1eb042b4-9f73-43bd-a4d2-961ae8abd28c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_1eb042b4-9f73-43bd-a4d2-961ae8abd28c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_743d2769-4959-4706-a9d1-09db308456bf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_743d2769-4959-4706-a9d1-09db308456bf" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDemandObligationMember_c7c8db51-1fd2-467b-bb98-c7f0a25e8b1a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateDemandObligationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermInvestmentsMember_751c9bdc-ff3c-4713-ace7-03bcae793d4a" xlink:to="loc_us-gaap_VariableRateDemandObligationMember_c7c8db51-1fd2-467b-bb98-c7f0a25e8b1a" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/FactoringofAccountsReceivableFactoringofAccountsReceivableDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#FactoringofAccountsReceivableFactoringofAccountsReceivableDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/FactoringofAccountsReceivableFactoringofAccountsReceivableDetails" xlink:type="extended" id="ie877bc87589c4944bff614ba175acb58_FactoringofAccountsReceivableFactoringofAccountsReceivableDetails">
    <link:loc xlink:type="locator" xlink:label="loc_amkr_FactoringofAccountsReceivableLineItems_c42d35b9-0d4f-49a9-b356-b062b670e979" xlink:href="amkr-20211231.xsd#amkr_FactoringofAccountsReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_AccountsReceivableSoldwithoutRecourse_76b92957-a0ae-45ea-be56-f1316cd332a4" xlink:href="amkr-20211231.xsd#amkr_AccountsReceivableSoldwithoutRecourse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_FactoringofAccountsReceivableLineItems_c42d35b9-0d4f-49a9-b356-b062b670e979" xlink:to="loc_amkr_AccountsReceivableSoldwithoutRecourse_76b92957-a0ae-45ea-be56-f1316cd332a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_FactoringofAccountsReceivableTable_25a6a8c3-36f1-40de-b900-db7a3ccfc8cf" xlink:href="amkr-20211231.xsd#amkr_FactoringofAccountsReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_amkr_FactoringofAccountsReceivableLineItems_c42d35b9-0d4f-49a9-b356-b062b670e979" xlink:to="loc_amkr_FactoringofAccountsReceivableTable_25a6a8c3-36f1-40de-b900-db7a3ccfc8cf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_FactoringofAccountsReceivableAxis_707f9e9f-66c5-4390-97cd-5ec6df42f2cd" xlink:href="amkr-20211231.xsd#amkr_FactoringofAccountsReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_amkr_FactoringofAccountsReceivableTable_25a6a8c3-36f1-40de-b900-db7a3ccfc8cf" xlink:to="loc_amkr_FactoringofAccountsReceivableAxis_707f9e9f-66c5-4390-97cd-5ec6df42f2cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_FactoringofAccountsReceivableDomain_707f9e9f-66c5-4390-97cd-5ec6df42f2cd_default" xlink:href="amkr-20211231.xsd#amkr_FactoringofAccountsReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_amkr_FactoringofAccountsReceivableAxis_707f9e9f-66c5-4390-97cd-5ec6df42f2cd" xlink:to="loc_amkr_FactoringofAccountsReceivableDomain_707f9e9f-66c5-4390-97cd-5ec6df42f2cd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_FactoringofAccountsReceivableDomain_20b2eeb6-9b79-41a2-aab5-a4e9da8f248c" xlink:href="amkr-20211231.xsd#amkr_FactoringofAccountsReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_amkr_FactoringofAccountsReceivableAxis_707f9e9f-66c5-4390-97cd-5ec6df42f2cd" xlink:to="loc_amkr_FactoringofAccountsReceivableDomain_20b2eeb6-9b79-41a2-aab5-a4e9da8f248c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TotalFactoredMember_dfdeef67-a23a-43d9-95e9-bd10ffa71d36" xlink:href="amkr-20211231.xsd#amkr_TotalFactoredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_FactoringofAccountsReceivableDomain_20b2eeb6-9b79-41a2-aab5-a4e9da8f248c" xlink:to="loc_amkr_TotalFactoredMember_dfdeef67-a23a-43d9-95e9-bd10ffa71d36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_FactoringFeesMember_76aa2148-5408-4e22-8a41-fd573269a878" xlink:href="amkr-20211231.xsd#amkr_FactoringFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_FactoringofAccountsReceivableDomain_20b2eeb6-9b79-41a2-aab5-a4e9da8f248c" xlink:to="loc_amkr_FactoringFeesMember_76aa2148-5408-4e22-8a41-fd573269a878" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/PropertyPlantandEquipmentDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#PropertyPlantandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/PropertyPlantandEquipmentDetails" xlink:type="extended" id="i30353c643eb44ffb8a52b95bc93f78ac_PropertyPlantandEquipmentDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_be0f3072-6164-49d3-a704-bf0a3bdb9d74" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_0e9dc977-2276-4e26-93c1-9a01517733ac" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_be0f3072-6164-49d3-a704-bf0a3bdb9d74" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_0e9dc977-2276-4e26-93c1-9a01517733ac" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_9a9cc2f5-b110-4568-abc5-36db22c6c390" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_be0f3072-6164-49d3-a704-bf0a3bdb9d74" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_9a9cc2f5-b110-4568-abc5-36db22c6c390" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_426680e2-88a8-4436-a8c2-6e501ce1df90" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_be0f3072-6164-49d3-a704-bf0a3bdb9d74" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_426680e2-88a8-4436-a8c2-6e501ce1df90" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_e881946e-3267-4399-9638-7c22a5c87c30" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_be0f3072-6164-49d3-a704-bf0a3bdb9d74" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_e881946e-3267-4399-9638-7c22a5c87c30" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_cda82089-7b34-4841-9527-aee45d29edec" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_be0f3072-6164-49d3-a704-bf0a3bdb9d74" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_cda82089-7b34-4841-9527-aee45d29edec" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_3a232196-8d96-4421-9c84-ba6da999f2f3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_be0f3072-6164-49d3-a704-bf0a3bdb9d74" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_3a232196-8d96-4421-9c84-ba6da999f2f3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_ed1307b3-27d6-4d03-90aa-2ea51f335918" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_be0f3072-6164-49d3-a704-bf0a3bdb9d74" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_ed1307b3-27d6-4d03-90aa-2ea51f335918" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_26434033-f30c-46fd-9b16-23728d91cca1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Depreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_be0f3072-6164-49d3-a704-bf0a3bdb9d74" xlink:to="loc_us-gaap_Depreciation_26434033-f30c-46fd-9b16-23728d91cca1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_bb7e8037-5d95-4c5b-9d72-d6dda4cd44c7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_be0f3072-6164-49d3-a704-bf0a3bdb9d74" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_bb7e8037-5d95-4c5b-9d72-d6dda4cd44c7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6003499d-3623-403c-8e98-22aeb369c928" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_bb7e8037-5d95-4c5b-9d72-d6dda4cd44c7" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6003499d-3623-403c-8e98-22aeb369c928" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_6003499d-3623-403c-8e98-22aeb369c928_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6003499d-3623-403c-8e98-22aeb369c928" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_6003499d-3623-403c-8e98-22aeb369c928_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_878f867d-e8ee-41d8-a00c-4189dd090e36" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6003499d-3623-403c-8e98-22aeb369c928" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_878f867d-e8ee-41d8-a00c-4189dd090e36" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember_626c9494-ecf1-45c6-9626-0a20329e33c2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_878f867d-e8ee-41d8-a00c-4189dd090e36" xlink:to="loc_us-gaap_LandMember_626c9494-ecf1-45c6-9626-0a20329e33c2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_7f549196-8bd6-48db-bac1-3698c2014a52" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_878f867d-e8ee-41d8-a00c-4189dd090e36" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_7f549196-8bd6-48db-bac1-3698c2014a52" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_951a90ad-c3b9-49ab-9ea4-edc9d5dd384d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_878f867d-e8ee-41d8-a00c-4189dd090e36" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_951a90ad-c3b9-49ab-9ea4-edc9d5dd384d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsHeldUnderCapitalLeasesMember_237fa3c8-4c0b-4880-b018-5fd50ddeefb9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsHeldUnderCapitalLeasesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_878f867d-e8ee-41d8-a00c-4189dd090e36" xlink:to="loc_us-gaap_AssetsHeldUnderCapitalLeasesMember_237fa3c8-4c0b-4880-b018-5fd50ddeefb9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_a4f1399c-dc3a-4b3c-a1aa-95d3795e0a67" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_878f867d-e8ee-41d8-a00c-4189dd090e36" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_a4f1399c-dc3a-4b3c-a1aa-95d3795e0a67" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SoftwareAndComputerEquipmentMember_918bb590-399c-428d-96bb-799707224cd4" xlink:href="amkr-20211231.xsd#amkr_SoftwareAndComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_878f867d-e8ee-41d8-a00c-4189dd090e36" xlink:to="loc_amkr_SoftwareAndComputerEquipmentMember_918bb590-399c-428d-96bb-799707224cd4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_dba756b4-5dc2-48b3-83ed-cb6f5f742eae" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_878f867d-e8ee-41d8-a00c-4189dd090e36" xlink:to="loc_us-gaap_ConstructionInProgressMember_dba756b4-5dc2-48b3-83ed-cb6f5f742eae" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/DebtLongTermDebtDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#DebtLongTermDebtDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/DebtLongTermDebtDetails" xlink:type="extended" id="iba05212558414beb96808ad9ac350ecb_DebtLongTermDebtDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_174bf61f-15dc-4e8c-ba01-eaac08c9d98b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_174bf61f-15dc-4e8c-ba01-eaac08c9d98b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_c625ffdd-ad6c-4bd5-ac1c-475d9d10c248" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_c625ffdd-ad6c-4bd5-ac1c-475d9d10c248" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtCurrent_b68b649f-c141-4c3a-9042-ed85e9da7a79" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_DebtCurrent_b68b649f-c141-4c3a-9042-ed85e9da7a79" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_f5a1e794-0a50-489c-84ef-d32f8a939aac" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_f5a1e794-0a50-489c-84ef-d32f8a939aac" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_bb67a106-4e9e-4bb6-865d-99960053ceed" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_bb67a106-4e9e-4bb6-865d-99960053ceed" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_5a104840-1b38-469f-92a6-99f0a4be62b7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_5a104840-1b38-469f-92a6-99f0a4be62b7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_5efa5728-72e2-48af-a01c-dbe5730f0b84" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_5efa5728-72e2-48af-a01c-dbe5730f0b84" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_badd31f5-9f7b-43f9-8e2b-fd8dedc8dbcd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_badd31f5-9f7b-43f9-8e2b-fd8dedc8dbcd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_0e4fa571-f703-41d6-a1e5-da5e1c58f9bf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_0e4fa571-f703-41d6-a1e5-da5e1c58f9bf" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_a196888a-e567-4a10-b927-63265f06b247" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_a196888a-e567-4a10-b927-63265f06b247" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_08ebdd52-10fb-4561-99b1-936076fd5cd6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_08ebdd52-10fb-4561-99b1-936076fd5cd6" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_4dfa5483-2b85-4918-8e10-edcad2bcadbf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_4dfa5483-2b85-4918-8e10-edcad2bcadbf" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtWeightedAverageInterestRate_9fb35b55-5915-4acc-9345-ec96f4a2958b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_LongtermDebtWeightedAverageInterestRate_9fb35b55-5915-4acc-9345-ec96f4a2958b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_172c180a-08d8-4d4b-a2b5-ac262bad3731" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_172c180a-08d8-4d4b-a2b5-ac262bad3731" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_fde55a25-86ef-4ea2-b657-0601d77a80d2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_LongTermDebt_fde55a25-86ef-4ea2-b657-0601d77a80d2" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_3cf7e331-d1d9-4fa9-a984-b68bda499dbd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ba7ee7e2-64f2-4bc6-933d-e130750682c6" xlink:to="loc_us-gaap_DebtInstrumentTable_3cf7e331-d1d9-4fa9-a984-b68bda499dbd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_ba6f0f33-e654-43ae-a0fe-b52211e745b0" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3cf7e331-d1d9-4fa9-a984-b68bda499dbd" xlink:to="loc_srt_RangeAxis_ba6f0f33-e654-43ae-a0fe-b52211e745b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_ba6f0f33-e654-43ae-a0fe-b52211e745b0_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_ba6f0f33-e654-43ae-a0fe-b52211e745b0" xlink:to="loc_srt_RangeMember_ba6f0f33-e654-43ae-a0fe-b52211e745b0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_5d9137c5-09c3-4343-be94-dc0e004538b4" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_ba6f0f33-e654-43ae-a0fe-b52211e745b0" xlink:to="loc_srt_RangeMember_5d9137c5-09c3-4343-be94-dc0e004538b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_9457ae7e-50ef-4857-b200-28b7201a4ecd" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_5d9137c5-09c3-4343-be94-dc0e004538b4" xlink:to="loc_srt_MinimumMember_9457ae7e-50ef-4857-b200-28b7201a4ecd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_bd156fc7-df2d-41ab-b45e-9a415e425905" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_5d9137c5-09c3-4343-be94-dc0e004538b4" xlink:to="loc_srt_MaximumMember_bd156fc7-df2d-41ab-b45e-9a415e425905" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_c0a1a428-8886-4538-a95f-e31e2ba48a50" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3cf7e331-d1d9-4fa9-a984-b68bda499dbd" xlink:to="loc_srt_StatementGeographicalAxis_c0a1a428-8886-4538-a95f-e31e2ba48a50" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_c0a1a428-8886-4538-a95f-e31e2ba48a50_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_c0a1a428-8886-4538-a95f-e31e2ba48a50" xlink:to="loc_srt_SegmentGeographicalDomain_c0a1a428-8886-4538-a95f-e31e2ba48a50_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_22969800-c1c3-4118-9935-72b79733b00f" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_c0a1a428-8886-4538-a95f-e31e2ba48a50" xlink:to="loc_srt_SegmentGeographicalDomain_22969800-c1c3-4118-9935-72b79733b00f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_KR_b67c2592-588a-49db-bcf2-d9ed148ce31d" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_KR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_22969800-c1c3-4118-9935-72b79733b00f" xlink:to="loc_country_KR_b67c2592-588a-49db-bcf2-d9ed148ce31d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_JP_6b11ad70-6331-4bcb-8a3c-87b54fbeeb07" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_JP"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_22969800-c1c3-4118-9935-72b79733b00f" xlink:to="loc_country_JP_6b11ad70-6331-4bcb-8a3c-87b54fbeeb07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_fa4cc789-4fb3-4e56-b192-727ca61981f2" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_22969800-c1c3-4118-9935-72b79733b00f" xlink:to="loc_country_CN_fa4cc789-4fb3-4e56-b192-727ca61981f2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_TW_34fd660c-7122-416b-936d-91884a90413f" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_TW"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_22969800-c1c3-4118-9935-72b79733b00f" xlink:to="loc_country_TW_34fd660c-7122-416b-936d-91884a90413f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_50a5905f-01ac-45d6-994c-d29abe108d8b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3cf7e331-d1d9-4fa9-a984-b68bda499dbd" xlink:to="loc_us-gaap_DebtInstrumentAxis_50a5905f-01ac-45d6-994c-d29abe108d8b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_50a5905f-01ac-45d6-994c-d29abe108d8b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_50a5905f-01ac-45d6-994c-d29abe108d8b" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_50a5905f-01ac-45d6-994c-d29abe108d8b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_50a5905f-01ac-45d6-994c-d29abe108d8b" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SeniorNotesDueSeptember2027Member_af523728-2d6b-447c-88cc-e5d67b275fa9" xlink:href="amkr-20211231.xsd#amkr_SeniorNotesDueSeptember2027Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_SeniorNotesDueSeptember2027Member_af523728-2d6b-447c-88cc-e5d67b275fa9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_96af6577-0c6d-43a8-8e7d-5b03c8313c23" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_96af6577-0c6d-43a8-8e7d-5b03c8313c23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_RevolvingCreditFacilityDueOctober2022Member_da19b7cf-d941-4d64-a5a4-a35ba6062d1e" xlink:href="amkr-20211231.xsd#amkr_RevolvingCreditFacilityDueOctober2022Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_RevolvingCreditFacilityDueOctober2022Member_da19b7cf-d941-4d64-a5a4-a35ba6062d1e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_RevolvingCreditFacilityDueOctober2021Member_a3d90a9f-60ee-40ba-b290-c460f15238f2" xlink:href="amkr-20211231.xsd#amkr_RevolvingCreditFacilityDueOctober2021Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_RevolvingCreditFacilityDueOctober2021Member_a3d90a9f-60ee-40ba-b290-c460f15238f2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanDueApril2023Member_ea765cfe-5b7f-4f3a-b90b-c4608822905a" xlink:href="amkr-20211231.xsd#amkr_TermLoanDueApril2023Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanDueApril2023Member_ea765cfe-5b7f-4f3a-b90b-c4608822905a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanFixedRateAt185DueApril2024Member_241dba24-ba1d-47c1-b847-8038dec9b1cb" xlink:href="amkr-20211231.xsd#amkr_TermLoanFixedRateAt185DueApril2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanFixedRateAt185DueApril2024Member_241dba24-ba1d-47c1-b847-8038dec9b1cb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanDueDecember2028Member_cff821b0-81cc-43a6-ad67-1757e4d007da" xlink:href="amkr-20211231.xsd#amkr_TermLoanDueDecember2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanDueDecember2028Member_cff821b0-81cc-43a6-ad67-1757e4d007da" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanFixedRateAt212DueDecember2028Member_f9391f75-a407-4ef9-9f39-f6f677d1050b" xlink:href="amkr-20211231.xsd#amkr_TermLoanFixedRateAt212DueDecember2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanFixedRateAt212DueDecember2028Member_f9391f75-a407-4ef9-9f39-f6f677d1050b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_ShorttermtermloanvariablerateMember_8d895ad6-04f6-4ba1-b787-2865c1c6d5c1" xlink:href="amkr-20211231.xsd#amkr_ShorttermtermloanvariablerateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_ShorttermtermloanvariablerateMember_8d895ad6-04f6-4ba1-b787-2865c1c6d5c1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanDueJune2022Member_1f8ac19b-2856-4929-abed-3b2c51a7324b" xlink:href="amkr-20211231.xsd#amkr_TermLoanDueJune2022Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanDueJune2022Member_1f8ac19b-2856-4929-abed-3b2c51a7324b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanFixedRateat0.60DueJuly2022Member_dd113d29-11ed-4bf1-9b3c-f4aaad54b1ee" xlink:href="amkr-20211231.xsd#amkr_TermLoanFixedRateat0.60DueJuly2022Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanFixedRateat0.60DueJuly2022Member_dd113d29-11ed-4bf1-9b3c-f4aaad54b1ee" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanFixedRateat1.30DueJuly2023Member_839511f8-c88c-4cbd-b686-a2e661dd8acc" xlink:href="amkr-20211231.xsd#amkr_TermLoanFixedRateat1.30DueJuly2023Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanFixedRateat1.30DueJuly2023Member_839511f8-c88c-4cbd-b686-a2e661dd8acc" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanFixedRateat1.35DueDecember2024Member_f3baa401-d58d-4d01-8ab9-e54cb6646287" xlink:href="amkr-20211231.xsd#amkr_TermLoanFixedRateat1.35DueDecember2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanFixedRateat1.35DueDecember2024Member_f3baa401-d58d-4d01-8ab9-e54cb6646287" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanFixedRateAt120DueDecember2025Member_3f0d130b-1530-4e38-b3c9-12c3a5e7da65" xlink:href="amkr-20211231.xsd#amkr_TermLoanFixedRateAt120DueDecember2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanFixedRateAt120DueDecember2025Member_3f0d130b-1530-4e38-b3c9-12c3a5e7da65" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanFixedRateAt12DueDecember2026Member_df8ff7f6-6b9a-4629-8663-0543f9ad8c8e" xlink:href="amkr-20211231.xsd#amkr_TermLoanFixedRateAt12DueDecember2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanFixedRateAt12DueDecember2026Member_df8ff7f6-6b9a-4629-8663-0543f9ad8c8e" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanLIBORplus1.60DueMarch2022Member_3ed27344-515d-447e-b325-360d375dc284" xlink:href="amkr-20211231.xsd#amkr_TermLoanLIBORplus1.60DueMarch2022Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanLIBORplus1.60DueMarch2022Member_3ed27344-515d-447e-b325-360d375dc284" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanLIBORplus1.40DueMarch2022Member_760489d4-0f9e-4364-b815-c90ce770abfd" xlink:href="amkr-20211231.xsd#amkr_TermLoanLIBORplus1.40DueMarch2022Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanLIBORplus1.40DueMarch2022Member_760489d4-0f9e-4364-b815-c90ce770abfd" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanLIBORPlus110DueMarch2024Member_9d410df2-6faa-4ca3-8cb1-ec848d0f2c59" xlink:href="amkr-20211231.xsd#amkr_TermLoanLIBORPlus110DueMarch2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanLIBORPlus110DueMarch2024Member_9d410df2-6faa-4ca3-8cb1-ec848d0f2c59" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanOneLIBORPlus110DueMarch2024Member_c419a056-988f-42b0-894d-0cc92670ca44" xlink:href="amkr-20211231.xsd#amkr_TermLoanOneLIBORPlus110DueMarch2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanOneLIBORPlus110DueMarch2024Member_c419a056-988f-42b0-894d-0cc92670ca44" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanTwoLIBORPlus110DueMarch2024Member_b8ce09d7-4130-4f78-8d72-1987574dd198" xlink:href="amkr-20211231.xsd#amkr_TermLoanTwoLIBORPlus110DueMarch2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_TermLoanTwoLIBORPlus110DueMarch2024Member_b8ce09d7-4130-4f78-8d72-1987574dd198" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SeniorSecuredRevolvingCreditFacilitydueJuly2023Member_c3ef86ff-5f0f-4262-954a-db976036c0cf" xlink:href="amkr-20211231.xsd#amkr_SeniorSecuredRevolvingCreditFacilitydueJuly2023Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_SeniorSecuredRevolvingCreditFacilitydueJuly2023Member_c3ef86ff-5f0f-4262-954a-db976036c0cf" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_RevolvingCreditFacilitydueDecember2024Member_95e8fc05-67a1-4ff5-9fae-74734605612d" xlink:href="amkr-20211231.xsd#amkr_RevolvingCreditFacilitydueDecember2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c9e138c9-49eb-473d-bb5e-2e40266da00f" xlink:to="loc_amkr_RevolvingCreditFacilitydueDecember2024Member_95e8fc05-67a1-4ff5-9fae-74734605612d" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_9247261e-454f-4204-8327-f854049c5527" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3cf7e331-d1d9-4fa9-a984-b68bda499dbd" xlink:to="loc_us-gaap_CreditFacilityAxis_9247261e-454f-4204-8327-f854049c5527" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_9247261e-454f-4204-8327-f854049c5527_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_9247261e-454f-4204-8327-f854049c5527" xlink:to="loc_us-gaap_CreditFacilityDomain_9247261e-454f-4204-8327-f854049c5527_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_81fd3c18-0d7d-44bd-8db5-1cb82d2a395e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_9247261e-454f-4204-8327-f854049c5527" xlink:to="loc_us-gaap_CreditFacilityDomain_81fd3c18-0d7d-44bd-8db5-1cb82d2a395e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_813bcfac-f2c6-4a2c-a077-f9ea3583deef" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_81fd3c18-0d7d-44bd-8db5-1cb82d2a395e" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_813bcfac-f2c6-4a2c-a077-f9ea3583deef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_daa23f01-2acb-4008-ab08-0572f71787c1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3cf7e331-d1d9-4fa9-a984-b68bda499dbd" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_daa23f01-2acb-4008-ab08-0572f71787c1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_daa23f01-2acb-4008-ab08-0572f71787c1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_daa23f01-2acb-4008-ab08-0572f71787c1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_daa23f01-2acb-4008-ab08-0572f71787c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_72bb5f9b-ec23-4a92-85e1-ca6420ea4992" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_daa23f01-2acb-4008-ab08-0572f71787c1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_72bb5f9b-ec23-4a92-85e1-ca6420ea4992" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_59ad3d06-e25c-4a41-85af-41cdae680d41" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_72bb5f9b-ec23-4a92-85e1-ca6420ea4992" xlink:to="loc_us-gaap_SeniorNotesMember_59ad3d06-e25c-4a41-85af-41cdae680d41" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_5866f0bd-822b-488c-b58d-39b606b7a1a1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_72bb5f9b-ec23-4a92-85e1-ca6420ea4992" xlink:to="loc_us-gaap_LineOfCreditMember_5866f0bd-822b-488c-b58d-39b606b7a1a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SubsidiaryTermLoansMember_034ef295-2f1d-42e2-856a-e4bd05fdc8a9" xlink:href="amkr-20211231.xsd#amkr_SubsidiaryTermLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_72bb5f9b-ec23-4a92-85e1-ca6420ea4992" xlink:to="loc_amkr_SubsidiaryTermLoansMember_034ef295-2f1d-42e2-856a-e4bd05fdc8a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_da753c2d-5191-4721-a7c9-69fb30d4924b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3cf7e331-d1d9-4fa9-a984-b68bda499dbd" xlink:to="loc_us-gaap_VariableRateAxis_da753c2d-5191-4721-a7c9-69fb30d4924b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_da753c2d-5191-4721-a7c9-69fb30d4924b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_da753c2d-5191-4721-a7c9-69fb30d4924b" xlink:to="loc_us-gaap_VariableRateDomain_da753c2d-5191-4721-a7c9-69fb30d4924b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_f6841fdd-b186-43d9-a1f8-f6647f888b24" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_da753c2d-5191-4721-a7c9-69fb30d4924b" xlink:to="loc_us-gaap_VariableRateDomain_f6841fdd-b186-43d9-a1f8-f6647f888b24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_ApplicableBankRateMember_5e387f03-fe90-4ab7-999f-39e86182bc3a" xlink:href="amkr-20211231.xsd#amkr_ApplicableBankRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_f6841fdd-b186-43d9-a1f8-f6647f888b24" xlink:to="loc_amkr_ApplicableBankRateMember_5e387f03-fe90-4ab7-999f-39e86182bc3a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_8235e8b5-f036-4a9d-9f30-e502309b018a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_f6841fdd-b186-43d9-a1f8-f6647f888b24" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_8235e8b5-f036-4a9d-9f30-e502309b018a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_5eee217d-e1ef-4fa4-b617-4dcb2b9f1f81" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3cf7e331-d1d9-4fa9-a984-b68bda499dbd" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_5eee217d-e1ef-4fa4-b617-4dcb2b9f1f81" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_5eee217d-e1ef-4fa4-b617-4dcb2b9f1f81_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_5eee217d-e1ef-4fa4-b617-4dcb2b9f1f81" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_5eee217d-e1ef-4fa4-b617-4dcb2b9f1f81_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_13973981-a8af-4125-812b-c6161cb16bca" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_5eee217d-e1ef-4fa4-b617-4dcb2b9f1f81" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_13973981-a8af-4125-812b-c6161cb16bca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_f57af79b-97d8-434c-b5f3-bc403a39c7d0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_13973981-a8af-4125-812b-c6161cb16bca" xlink:to="loc_us-gaap_SubsequentEventMember_f57af79b-97d8-434c-b5f3-bc403a39c7d0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/DebtInterestRatesDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#DebtInterestRatesDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/DebtInterestRatesDetails" xlink:type="extended" id="i87388f94ed7046999cc9350109f69c67_DebtInterestRatesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_c5bda4a9-c6fb-402c-9b0f-3958c494e0b4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_16357f19-5ac5-4271-92dd-3fb73e7b070a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c5bda4a9-c6fb-402c-9b0f-3958c494e0b4" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_16357f19-5ac5-4271-92dd-3fb73e7b070a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_2f564547-4ae4-4977-8313-6ebb1b19fab3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c5bda4a9-c6fb-402c-9b0f-3958c494e0b4" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_2f564547-4ae4-4977-8313-6ebb1b19fab3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_c50e6e8c-69d2-4117-8628-ac36817993c1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c5bda4a9-c6fb-402c-9b0f-3958c494e0b4" xlink:to="loc_us-gaap_DebtInstrumentTable_c50e6e8c-69d2-4117-8628-ac36817993c1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_7557f18d-cb43-471b-9295-865febbab341" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_c50e6e8c-69d2-4117-8628-ac36817993c1" xlink:to="loc_us-gaap_VariableRateAxis_7557f18d-cb43-471b-9295-865febbab341" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_7557f18d-cb43-471b-9295-865febbab341_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_7557f18d-cb43-471b-9295-865febbab341" xlink:to="loc_us-gaap_VariableRateDomain_7557f18d-cb43-471b-9295-865febbab341_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_01c4e3b3-513b-4187-be57-9815f0ba86b7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_7557f18d-cb43-471b-9295-865febbab341" xlink:to="loc_us-gaap_VariableRateDomain_01c4e3b3-513b-4187-be57-9815f0ba86b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_ApplicableBankRateMember_ddfca3d3-1d80-4677-bb0d-c47b116b217d" xlink:href="amkr-20211231.xsd#amkr_ApplicableBankRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_01c4e3b3-513b-4187-be57-9815f0ba86b7" xlink:to="loc_amkr_ApplicableBankRateMember_ddfca3d3-1d80-4677-bb0d-c47b116b217d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_f94d28a4-41dd-42ed-9ad2-b77d72ad22a4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_01c4e3b3-513b-4187-be57-9815f0ba86b7" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_f94d28a4-41dd-42ed-9ad2-b77d72ad22a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_4dd80ed4-183c-470d-b30c-30cc5c04451e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_c50e6e8c-69d2-4117-8628-ac36817993c1" xlink:to="loc_us-gaap_CreditFacilityAxis_4dd80ed4-183c-470d-b30c-30cc5c04451e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_4dd80ed4-183c-470d-b30c-30cc5c04451e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_4dd80ed4-183c-470d-b30c-30cc5c04451e" xlink:to="loc_us-gaap_CreditFacilityDomain_4dd80ed4-183c-470d-b30c-30cc5c04451e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_adbcba52-9290-4310-bc0e-574a47c03770" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_4dd80ed4-183c-470d-b30c-30cc5c04451e" xlink:to="loc_us-gaap_CreditFacilityDomain_adbcba52-9290-4310-bc0e-574a47c03770" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_894ec570-431f-4f64-97da-3ff081e2663f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_adbcba52-9290-4310-bc0e-574a47c03770" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_894ec570-431f-4f64-97da-3ff081e2663f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_83cb7eb8-de78-4517-ac18-e24eeafb41b8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_c50e6e8c-69d2-4117-8628-ac36817993c1" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_83cb7eb8-de78-4517-ac18-e24eeafb41b8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_83cb7eb8-de78-4517-ac18-e24eeafb41b8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_83cb7eb8-de78-4517-ac18-e24eeafb41b8" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_83cb7eb8-de78-4517-ac18-e24eeafb41b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_874614bb-392c-4033-b94e-729970a7f24e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_83cb7eb8-de78-4517-ac18-e24eeafb41b8" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_874614bb-392c-4033-b94e-729970a7f24e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_5675670c-59da-4588-9f15-f3981cdff55a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_874614bb-392c-4033-b94e-729970a7f24e" xlink:to="loc_us-gaap_LineOfCreditMember_5675670c-59da-4588-9f15-f3981cdff55a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SubsidiaryTermLoansMember_0a8824f0-4684-4721-9ac3-deb70002f5b7" xlink:href="amkr-20211231.xsd#amkr_SubsidiaryTermLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_874614bb-392c-4033-b94e-729970a7f24e" xlink:to="loc_amkr_SubsidiaryTermLoansMember_0a8824f0-4684-4721-9ac3-deb70002f5b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_88018076-abd6-4623-80ce-4de5f09f65c6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_c50e6e8c-69d2-4117-8628-ac36817993c1" xlink:to="loc_us-gaap_DebtInstrumentAxis_88018076-abd6-4623-80ce-4de5f09f65c6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_88018076-abd6-4623-80ce-4de5f09f65c6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_88018076-abd6-4623-80ce-4de5f09f65c6" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_88018076-abd6-4623-80ce-4de5f09f65c6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_8bf00b3f-7a45-4b84-8a61-b7a5b52c841c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_88018076-abd6-4623-80ce-4de5f09f65c6" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_8bf00b3f-7a45-4b84-8a61-b7a5b52c841c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanDueApril2023Member_3b5d0ff2-bec0-4755-99ff-c8f37d36dfdb" xlink:href="amkr-20211231.xsd#amkr_TermLoanDueApril2023Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_8bf00b3f-7a45-4b84-8a61-b7a5b52c841c" xlink:to="loc_amkr_TermLoanDueApril2023Member_3b5d0ff2-bec0-4755-99ff-c8f37d36dfdb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_ShorttermtermloanvariablerateMember_a988f959-b2ac-48ab-b196-009f98b1cb77" xlink:href="amkr-20211231.xsd#amkr_ShorttermtermloanvariablerateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_8bf00b3f-7a45-4b84-8a61-b7a5b52c841c" xlink:to="loc_amkr_ShorttermtermloanvariablerateMember_a988f959-b2ac-48ab-b196-009f98b1cb77" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanLIBORplus1.60DueMarch2022Member_35610e9c-81f1-4e7a-80fa-1a7be0e1c82f" xlink:href="amkr-20211231.xsd#amkr_TermLoanLIBORplus1.60DueMarch2022Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_8bf00b3f-7a45-4b84-8a61-b7a5b52c841c" xlink:to="loc_amkr_TermLoanLIBORplus1.60DueMarch2022Member_35610e9c-81f1-4e7a-80fa-1a7be0e1c82f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanLIBORplus1.40DueMarch2022Member_521bb642-9f05-484c-bd09-843075f413f6" xlink:href="amkr-20211231.xsd#amkr_TermLoanLIBORplus1.40DueMarch2022Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_8bf00b3f-7a45-4b84-8a61-b7a5b52c841c" xlink:to="loc_amkr_TermLoanLIBORplus1.40DueMarch2022Member_521bb642-9f05-484c-bd09-843075f413f6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_RevolvingCreditFacilitydueDecember2024Member_30dcbc97-bbda-4dd9-af56-c4804abad90c" xlink:href="amkr-20211231.xsd#amkr_RevolvingCreditFacilitydueDecember2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_8bf00b3f-7a45-4b84-8a61-b7a5b52c841c" xlink:to="loc_amkr_RevolvingCreditFacilitydueDecember2024Member_30dcbc97-bbda-4dd9-af56-c4804abad90c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanDueDecember2028Member_8afa2e28-258b-4e4a-b831-e0f0003e1a35" xlink:href="amkr-20211231.xsd#amkr_TermLoanDueDecember2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_8bf00b3f-7a45-4b84-8a61-b7a5b52c841c" xlink:to="loc_amkr_TermLoanDueDecember2028Member_8afa2e28-258b-4e4a-b831-e0f0003e1a35" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TermLoanLIBORPlus110DueMarch2024Member_52d034bc-8212-4f54-877f-a7df1830d0af" xlink:href="amkr-20211231.xsd#amkr_TermLoanLIBORPlus110DueMarch2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_8bf00b3f-7a45-4b84-8a61-b7a5b52c841c" xlink:to="loc_amkr_TermLoanLIBORPlus110DueMarch2024Member_52d034bc-8212-4f54-877f-a7df1830d0af" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_afafb6f1-57ce-4507-beae-359d24f32c18" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_c50e6e8c-69d2-4117-8628-ac36817993c1" xlink:to="loc_srt_StatementGeographicalAxis_afafb6f1-57ce-4507-beae-359d24f32c18" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_afafb6f1-57ce-4507-beae-359d24f32c18_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_afafb6f1-57ce-4507-beae-359d24f32c18" xlink:to="loc_srt_SegmentGeographicalDomain_afafb6f1-57ce-4507-beae-359d24f32c18_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_7191b538-a820-4186-a1d9-e6bbb3b61f21" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_afafb6f1-57ce-4507-beae-359d24f32c18" xlink:to="loc_srt_SegmentGeographicalDomain_7191b538-a820-4186-a1d9-e6bbb3b61f21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_KR_be641026-7aad-4e26-8b49-63d2f6db5695" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_KR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_7191b538-a820-4186-a1d9-e6bbb3b61f21" xlink:to="loc_country_KR_be641026-7aad-4e26-8b49-63d2f6db5695" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_JP_d47a22c1-670d-4486-8c5d-a1006085c421" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_JP"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_7191b538-a820-4186-a1d9-e6bbb3b61f21" xlink:to="loc_country_JP_d47a22c1-670d-4486-8c5d-a1006085c421" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_79a7c58f-1507-46a6-a922-5b452ff74377" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_7191b538-a820-4186-a1d9-e6bbb3b61f21" xlink:to="loc_country_CN_79a7c58f-1507-46a6-a922-5b452ff74377" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_TW_1694a4ca-236d-4d81-8237-e62cb78cff25" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_TW"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_7191b538-a820-4186-a1d9-e6bbb3b61f21" xlink:to="loc_country_TW_1694a4ca-236d-4d81-8237-e62cb78cff25" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/PensionandSeverancePlansKoreanSeverancePlanDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#PensionandSeverancePlansKoreanSeverancePlanDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/PensionandSeverancePlansKoreanSeverancePlanDetails" xlink:type="extended" id="ib205f0270fbc4637a26e5219ea3eb604_PensionandSeverancePlansKoreanSeverancePlanDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_21c34cf4-3150-4968-9057-50508fc7b896" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_DeferredCompensationLiabilityCurrentAndNoncurrentRollForward_0af4a16e-2fad-4b40-9098-468d0e441013" xlink:href="amkr-20211231.xsd#amkr_DeferredCompensationLiabilityCurrentAndNoncurrentRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_21c34cf4-3150-4968-9057-50508fc7b896" xlink:to="loc_amkr_DeferredCompensationLiabilityCurrentAndNoncurrentRollForward_0af4a16e-2fad-4b40-9098-468d0e441013" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent_3f760bd4-1d4a-4aaf-9fc9-dd0bfe1a996c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_DeferredCompensationLiabilityCurrentAndNoncurrentRollForward_0af4a16e-2fad-4b40-9098-468d0e441013" xlink:to="loc_us-gaap_DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent_3f760bd4-1d4a-4aaf-9fc9-dd0bfe1a996c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_ProvisionOfSeveranceBenefits_63e501da-2c14-4505-95a4-bb82c81c5c89" xlink:href="amkr-20211231.xsd#amkr_ProvisionOfSeveranceBenefits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_DeferredCompensationLiabilityCurrentAndNoncurrentRollForward_0af4a16e-2fad-4b40-9098-468d0e441013" xlink:to="loc_amkr_ProvisionOfSeveranceBenefits_63e501da-2c14-4505-95a4-bb82c81c5c89" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_PaymentsForEmployeeSeverance_9ab1fa07-feb4-43f8-88be-a46070005dc4" xlink:href="amkr-20211231.xsd#amkr_PaymentsForEmployeeSeverance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_DeferredCompensationLiabilityCurrentAndNoncurrentRollForward_0af4a16e-2fad-4b40-9098-468d0e441013" xlink:to="loc_amkr_PaymentsForEmployeeSeverance_9ab1fa07-feb4-43f8-88be-a46070005dc4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SeveranceBenefitsGainLossTranslationAdjustments_e33b0da6-78d3-44e7-8a53-673b7475b087" xlink:href="amkr-20211231.xsd#amkr_SeveranceBenefitsGainLossTranslationAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_DeferredCompensationLiabilityCurrentAndNoncurrentRollForward_0af4a16e-2fad-4b40-9098-468d0e441013" xlink:to="loc_amkr_SeveranceBenefitsGainLossTranslationAdjustments_e33b0da6-78d3-44e7-8a53-673b7475b087" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent_0d585ba7-2af4-4176-9985-9ee037af3339" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_PaymentsRemainingWithLocalPensionFund_2786a02d-4522-4329-bed6-0c7f664b7410" xlink:href="amkr-20211231.xsd#amkr_PaymentsRemainingWithLocalPensionFund"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_21c34cf4-3150-4968-9057-50508fc7b896" xlink:to="loc_amkr_PaymentsRemainingWithLocalPensionFund_2786a02d-4522-4329-bed6-0c7f664b7410" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PostemploymentBenefitsLiabilityCurrentAndNoncurrent_6a457b06-b449-4a4d-8106-9d1785e39edf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PostemploymentBenefitsLiabilityCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_21c34cf4-3150-4968-9057-50508fc7b896" xlink:to="loc_us-gaap_PostemploymentBenefitsLiabilityCurrentAndNoncurrent_6a457b06-b449-4a4d-8106-9d1785e39edf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PostemploymentBenefitsLiabilityCurrent_5e840945-a1cb-4ff2-ab52-549f2500f81e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PostemploymentBenefitsLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_21c34cf4-3150-4968-9057-50508fc7b896" xlink:to="loc_us-gaap_PostemploymentBenefitsLiabilityCurrent_5e840945-a1cb-4ff2-ab52-549f2500f81e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PostemploymentBenefitsLiabilityNoncurrent_c323afdc-7e9f-4d1c-b01d-3c782356f59d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PostemploymentBenefitsLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_21c34cf4-3150-4968-9057-50508fc7b896" xlink:to="loc_us-gaap_PostemploymentBenefitsLiabilityNoncurrent_c323afdc-7e9f-4d1c-b01d-3c782356f59d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTitleOfIndividualAndByTypeOfDeferredCompensationTable_bd486617-d255-4ad6-9e3d-78a65abaab67" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTitleOfIndividualAndByTypeOfDeferredCompensationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_21c34cf4-3150-4968-9057-50508fc7b896" xlink:to="loc_us-gaap_ScheduleOfDeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTitleOfIndividualAndByTypeOfDeferredCompensationTable_bd486617-d255-4ad6-9e3d-78a65abaab67" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_OtherDeferredCashCompensationAxis_feb9c2c0-d3f2-4924-80a9-01ba0a76dd2c" xlink:href="amkr-20211231.xsd#amkr_OtherDeferredCashCompensationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTitleOfIndividualAndByTypeOfDeferredCompensationTable_bd486617-d255-4ad6-9e3d-78a65abaab67" xlink:to="loc_amkr_OtherDeferredCashCompensationAxis_feb9c2c0-d3f2-4924-80a9-01ba0a76dd2c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_OtherDeferredCashCompensationDomain_feb9c2c0-d3f2-4924-80a9-01ba0a76dd2c_default" xlink:href="amkr-20211231.xsd#amkr_OtherDeferredCashCompensationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_amkr_OtherDeferredCashCompensationAxis_feb9c2c0-d3f2-4924-80a9-01ba0a76dd2c" xlink:to="loc_amkr_OtherDeferredCashCompensationDomain_feb9c2c0-d3f2-4924-80a9-01ba0a76dd2c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_OtherDeferredCashCompensationDomain_d7f0f3a9-81b0-4b06-b480-921ed698782e" xlink:href="amkr-20211231.xsd#amkr_OtherDeferredCashCompensationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_amkr_OtherDeferredCashCompensationAxis_feb9c2c0-d3f2-4924-80a9-01ba0a76dd2c" xlink:to="loc_amkr_OtherDeferredCashCompensationDomain_d7f0f3a9-81b0-4b06-b480-921ed698782e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_KoreanSeverancePlanMember_271e192d-fc08-448e-b493-aea966cc40a2" xlink:href="amkr-20211231.xsd#amkr_KoreanSeverancePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_amkr_OtherDeferredCashCompensationDomain_d7f0f3a9-81b0-4b06-b480-921ed698782e" xlink:to="loc_amkr_KoreanSeverancePlanMember_271e192d-fc08-448e-b493-aea966cc40a2" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/PensionandSeverancePlansImpactonAccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#PensionandSeverancePlansImpactonAccumulatedOtherComprehensiveIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/PensionandSeverancePlansImpactonAccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended" id="i8bab0e91dd3848bbb111387da83edff8_PensionandSeverancePlansImpactonAccumulatedOtherComprehensiveIncomeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_87ff9e42-e1e5-4832-ae62-323fa82616bc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_8eb8061f-63f2-434c-bdcb-ff644d8a30fc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_87ff9e42-e1e5-4832-ae62-323fa82616bc" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_8eb8061f-63f2-434c-bdcb-ff644d8a30fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_f9ff0cb3-cd1c-4b8d-a825-a503165f8a66" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_8eb8061f-63f2-434c-bdcb-ff644d8a30fc" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_f9ff0cb3-cd1c-4b8d-a825-a503165f8a66" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_956276aa-00a3-4eff-af5f-961b8e7984e4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_8eb8061f-63f2-434c-bdcb-ff644d8a30fc" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_956276aa-00a3-4eff-af5f-961b8e7984e4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_0dbf9aef-0e90-44bf-8240-fbe1761cf936" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_8eb8061f-63f2-434c-bdcb-ff644d8a30fc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_0dbf9aef-0e90-44bf-8240-fbe1761cf936" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_59c8d25d-d357-404c-81aa-271d214ea94d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_8eb8061f-63f2-434c-bdcb-ff644d8a30fc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_59c8d25d-d357-404c-81aa-271d214ea94d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_6452d94d-28bf-437c-b0d0-b6b98997188e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_bf2a380c-37c1-4b7b-b277-c58b6e3359f7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_87ff9e42-e1e5-4832-ae62-323fa82616bc" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_bf2a380c-37c1-4b7b-b277-c58b6e3359f7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_0be3f56f-de20-468d-8db5-be060e3dd6ab" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_bf2a380c-37c1-4b7b-b277-c58b6e3359f7" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_0be3f56f-de20-468d-8db5-be060e3dd6ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_0be3f56f-de20-468d-8db5-be060e3dd6ab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_0be3f56f-de20-468d-8db5-be060e3dd6ab" xlink:to="loc_us-gaap_EquityComponentDomain_0be3f56f-de20-468d-8db5-be060e3dd6ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_a043327c-7f4d-4a56-95cc-6c3d70ab9fc9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_0be3f56f-de20-468d-8db5-be060e3dd6ab" xlink:to="loc_us-gaap_EquityComponentDomain_a043327c-7f4d-4a56-95cc-6c3d70ab9fc9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterestMember_64ecb0ee-bb61-425e-a541-9895e4ddb5a1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a043327c-7f4d-4a56-95cc-6c3d70ab9fc9" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterestMember_64ecb0ee-bb61-425e-a541-9895e4ddb5a1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetGainLossIncludingPortionAttributableToNoncontrollingInterestMember_4e290fd8-8a67-4e41-9ece-9705c640f62f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetGainLossIncludingPortionAttributableToNoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a043327c-7f4d-4a56-95cc-6c3d70ab9fc9" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetGainLossIncludingPortionAttributableToNoncontrollingInterestMember_4e290fd8-8a67-4e41-9ece-9705c640f62f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentIncludingPortionAttributableToNoncontrollingInterestMember_0d96ff4f-c2ea-4ced-9dd3-b70f019c9912" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentIncludingPortionAttributableToNoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a043327c-7f4d-4a56-95cc-6c3d70ab9fc9" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentIncludingPortionAttributableToNoncontrollingInterestMember_0d96ff4f-c2ea-4ced-9dd3-b70f019c9912" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/PensionandSeverancePlansDefinedBenefitPlansAllocationofplanassetsDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#PensionandSeverancePlansDefinedBenefitPlansAllocationofplanassetsDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/PensionandSeverancePlansDefinedBenefitPlansAllocationofplanassetsDetails" xlink:type="extended" id="if3ab8ea216014001b05c7888127e2253_PensionandSeverancePlansDefinedBenefitPlansAllocationofplanassetsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_ccba6450-6f93-4650-b0b9-6e8fea29a24f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_680007aa-d8fe-447c-b244-eae12b2af0a6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_ccba6450-6f93-4650-b0b9-6e8fea29a24f" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_680007aa-d8fe-447c-b244-eae12b2af0a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_ad354797-b666-4d17-a01b-30742a44205a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_ccba6450-6f93-4650-b0b9-6e8fea29a24f" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_ad354797-b666-4d17-a01b-30742a44205a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ec314942-5855-405f-a9e6-b6c9b6521afb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_ccba6450-6f93-4650-b0b9-6e8fea29a24f" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ec314942-5855-405f-a9e6-b6c9b6521afb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1958efbc-a9b7-4b9c-a164-8d8c04ad3015" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ec314942-5855-405f-a9e6-b6c9b6521afb" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1958efbc-a9b7-4b9c-a164-8d8c04ad3015" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1958efbc-a9b7-4b9c-a164-8d8c04ad3015_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1958efbc-a9b7-4b9c-a164-8d8c04ad3015" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1958efbc-a9b7-4b9c-a164-8d8c04ad3015_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_347408f6-270f-4f12-8300-6d554d955aa1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1958efbc-a9b7-4b9c-a164-8d8c04ad3015" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_347408f6-270f-4f12-8300-6d554d955aa1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_5d0cb400-9703-4ee3-b1c6-22b84c94c785" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_347408f6-270f-4f12-8300-6d554d955aa1" xlink:to="loc_us-gaap_ForeignPlanMember_5d0cb400-9703-4ee3-b1c6-22b84c94c785" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_JP_a5893dd9-b1de-4443-8205-b840caf27686" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_JP"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignPlanMember_5d0cb400-9703-4ee3-b1c6-22b84c94c785" xlink:to="loc_country_JP_a5893dd9-b1de-4443-8205-b840caf27686" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_KR_d404dadc-8596-42ca-b8c5-23041c401676" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_KR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignPlanMember_5d0cb400-9703-4ee3-b1c6-22b84c94c785" xlink:to="loc_country_KR_d404dadc-8596-42ca-b8c5-23041c401676" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_PH_cfd1b489-c0b8-4957-80bd-beb9594ccf62" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_PH"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignPlanMember_5d0cb400-9703-4ee3-b1c6-22b84c94c785" xlink:to="loc_country_PH_cfd1b489-c0b8-4957-80bd-beb9594ccf62" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_74b219d7-aa6f-4fa1-96c3-f5bc1fb35edf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ec314942-5855-405f-a9e6-b6c9b6521afb" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_74b219d7-aa6f-4fa1-96c3-f5bc1fb35edf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_74b219d7-aa6f-4fa1-96c3-f5bc1fb35edf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_74b219d7-aa6f-4fa1-96c3-f5bc1fb35edf" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_74b219d7-aa6f-4fa1-96c3-f5bc1fb35edf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9499fd85-4e76-41e3-a56b-3f4ce417a141" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_74b219d7-aa6f-4fa1-96c3-f5bc1fb35edf" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9499fd85-4e76-41e3-a56b-3f4ce417a141" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_13818a60-3424-4733-8a92-8168de45696f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9499fd85-4e76-41e3-a56b-3f4ce417a141" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_13818a60-3424-4733-8a92-8168de45696f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_8c5d66ac-bd0c-4ae9-9802-9311e18eed9e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9499fd85-4e76-41e3-a56b-3f4ce417a141" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_8c5d66ac-bd0c-4ae9-9802-9311e18eed9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_164470ee-4f87-4c3a-8375-d90dea932c5b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ec314942-5855-405f-a9e6-b6c9b6521afb" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_164470ee-4f87-4c3a-8375-d90dea932c5b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_164470ee-4f87-4c3a-8375-d90dea932c5b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_164470ee-4f87-4c3a-8375-d90dea932c5b" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_164470ee-4f87-4c3a-8375-d90dea932c5b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_164470ee-4f87-4c3a-8375-d90dea932c5b" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_043b72af-d3e1-4a14-84ce-46b9b4253d56" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDebtSecurityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:to="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_043b72af-d3e1-4a14-84ce-46b9b4253d56" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_GovernmentBondsMember_0ae8b7bf-6f80-4dca-955e-86e0560091e7" xlink:href="amkr-20211231.xsd#amkr_GovernmentBondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_043b72af-d3e1-4a14-84ce-46b9b4253d56" xlink:to="loc_amkr_GovernmentBondsMember_0ae8b7bf-6f80-4dca-955e-86e0560091e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_4c3370e6-a1b3-4261-85e9-ed52a10a8eab" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_043b72af-d3e1-4a14-84ce-46b9b4253d56" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_4c3370e6-a1b3-4261-85e9-ed52a10a8eab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TreasuryNotesMember_58c8cf08-e844-467e-8396-b70abb113a2b" xlink:href="amkr-20211231.xsd#amkr_TreasuryNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_043b72af-d3e1-4a14-84ce-46b9b4253d56" xlink:to="loc_amkr_TreasuryNotesMember_58c8cf08-e844-467e-8396-b70abb113a2b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_6d8c0c38-d522-42a9-a806-49b3587553f7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_6d8c0c38-d522-42a9-a806-49b3587553f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_d47979fe-bf79-4716-a359-304b34b9fc1c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:to="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_d47979fe-bf79-4716-a359-304b34b9fc1c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesMember_af110f43-0202-4818-83f7-91c0e0f4b6d9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:to="loc_us-gaap_EquitySecuritiesMember_af110f43-0202-4818-83f7-91c0e0f4b6d9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_MutualAndCommingledEquityFundsMember_d94f4d50-8102-4463-87dc-0bb99dddd5f3" xlink:href="amkr-20211231.xsd#amkr_MutualAndCommingledEquityFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:to="loc_amkr_MutualAndCommingledEquityFundsMember_d94f4d50-8102-4463-87dc-0bb99dddd5f3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_MutualAndCommingledDebtFundsMember_af342125-3943-4291-91a2-bceced35a14e" xlink:href="amkr-20211231.xsd#amkr_MutualAndCommingledDebtFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:to="loc_amkr_MutualAndCommingledDebtFundsMember_af342125-3943-4291-91a2-bceced35a14e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_ForeignGuaranteedInvestmentContractMember_38b9792a-53de-43b0-bd24-4f196bac9c09" xlink:href="amkr-20211231.xsd#amkr_ForeignGuaranteedInvestmentContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:to="loc_amkr_ForeignGuaranteedInvestmentContractMember_38b9792a-53de-43b0-bd24-4f196bac9c09" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_TaiwanRetirementFundMember_068f6abe-3ac7-4fbe-9cb5-1cad63bf34a0" xlink:href="amkr-20211231.xsd#amkr_TaiwanRetirementFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:to="loc_amkr_TaiwanRetirementFundMember_068f6abe-3ac7-4fbe-9cb5-1cad63bf34a0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_OtherInvestmentTypeMember_697abcfb-411d-482a-a1cf-c9fc1858ad47" xlink:href="amkr-20211231.xsd#amkr_OtherInvestmentTypeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_83423cc7-af5e-4aa9-8b9a-d7b071596292" xlink:to="loc_amkr_OtherInvestmentTypeMember_697abcfb-411d-482a-a1cf-c9fc1858ad47" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/AccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#AccumulatedOtherComprehensiveIncomeLossDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/AccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="extended" id="id09358095ffa4190993a7a11dc17198c_AccumulatedOtherComprehensiveIncomeLossDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_29111866-8938-4401-880a-91aff0d08cfc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_b155e498-5d14-4505-b24b-7496865ca0fc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_29111866-8938-4401-880a-91aff0d08cfc" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_b155e498-5d14-4505-b24b-7496865ca0fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_e6d49403-b311-49f2-8187-a36eeac8a97f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_b155e498-5d14-4505-b24b-7496865ca0fc" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_e6d49403-b311-49f2-8187-a36eeac8a97f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_735fcf76-d695-4582-a1ba-7c54cf3b3e76" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_b155e498-5d14-4505-b24b-7496865ca0fc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_735fcf76-d695-4582-a1ba-7c54cf3b3e76" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_e458fbb4-9b3c-4316-8430-4dadad5d01a4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_b155e498-5d14-4505-b24b-7496865ca0fc" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_e458fbb4-9b3c-4316-8430-4dadad5d01a4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_da00ad06-a40d-41cb-b77b-788142d645b9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_b155e498-5d14-4505-b24b-7496865ca0fc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_da00ad06-a40d-41cb-b77b-788142d645b9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_6736c348-8314-4949-a2b1-d60f199f99a8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_68d8c009-fbad-47dd-be5a-3d9dc9e1ae8a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_29111866-8938-4401-880a-91aff0d08cfc" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_68d8c009-fbad-47dd-be5a-3d9dc9e1ae8a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_d72eb047-0f04-4b8f-962a-02dac5fb8305" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_68d8c009-fbad-47dd-be5a-3d9dc9e1ae8a" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_d72eb047-0f04-4b8f-962a-02dac5fb8305" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_d72eb047-0f04-4b8f-962a-02dac5fb8305_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d72eb047-0f04-4b8f-962a-02dac5fb8305" xlink:to="loc_us-gaap_EquityComponentDomain_d72eb047-0f04-4b8f-962a-02dac5fb8305_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_7628b14e-e753-4ffb-adbb-baaf9b9db619" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d72eb047-0f04-4b8f-962a-02dac5fb8305" xlink:to="loc_us-gaap_EquityComponentDomain_7628b14e-e753-4ffb-adbb-baaf9b9db619" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_c4c5d406-cfb2-4e88-96d5-17ee95fd0a51" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7628b14e-e753-4ffb-adbb-baaf9b9db619" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_c4c5d406-cfb2-4e88-96d5-17ee95fd0a51" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_08018ce3-fcc5-4c23-82ed-c994f30548ce" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_c4c5d406-cfb2-4e88-96d5-17ee95fd0a51" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_08018ce3-fcc5-4c23-82ed-c994f30548ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_2b5065eb-c220-4675-ad19-7f8371c7ee6b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_c4c5d406-cfb2-4e88-96d5-17ee95fd0a51" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_2b5065eb-c220-4675-ad19-7f8371c7ee6b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_b1a055f0-b13d-4ada-8505-fff8ab66eb3c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7628b14e-e753-4ffb-adbb-baaf9b9db619" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_b1a055f0-b13d-4ada-8505-fff8ab66eb3c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/DerivativesDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#DerivativesDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/DerivativesDetails" xlink:type="extended" id="i2acde877868f42e3bc2becdbaf3ec003_DerivativesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_8c8f13f4-81f8-41d2-8bc1-78e081bd12a0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotionalAmount_80177c01-f57e-403b-85ca-7beafcb80408" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssetNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_8c8f13f4-81f8-41d2-8bc1-78e081bd12a0" xlink:to="loc_us-gaap_DerivativeAssetNotionalAmount_80177c01-f57e-403b-85ca-7beafcb80408" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_e3071a9a-9716-4dab-a4c8-019894e7d945" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_8c8f13f4-81f8-41d2-8bc1-78e081bd12a0" xlink:to="loc_us-gaap_DerivativeAssets_e3071a9a-9716-4dab-a4c8-019894e7d945" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNet_22c29de7-42ed-4425-ab39-dbf3b266b9ca" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeGainLossOnDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_8c8f13f4-81f8-41d2-8bc1-78e081bd12a0" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNet_22c29de7-42ed-4425-ab39-dbf3b266b9ca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_ab64384d-2d1c-4bfd-ba5f-40990e21aa9d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_8c8f13f4-81f8-41d2-8bc1-78e081bd12a0" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_ab64384d-2d1c-4bfd-ba5f-40990e21aa9d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_0c8cc918-e8ae-46ba-b58c-375c036b17c6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_ab64384d-2d1c-4bfd-ba5f-40990e21aa9d" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_0c8cc918-e8ae-46ba-b58c-375c036b17c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_0c8cc918-e8ae-46ba-b58c-375c036b17c6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_0c8cc918-e8ae-46ba-b58c-375c036b17c6" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_0c8cc918-e8ae-46ba-b58c-375c036b17c6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_82455a57-f13d-41bf-9da6-b9c45ba00659" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_0c8cc918-e8ae-46ba-b58c-375c036b17c6" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_82455a57-f13d-41bf-9da6-b9c45ba00659" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_8d614960-925b-410f-ad2e-fb1453ee800e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_82455a57-f13d-41bf-9da6-b9c45ba00659" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_8d614960-925b-410f-ad2e-fb1453ee800e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CurrencyAxis_990bfda8-2229-4593-99f4-3afc4f3eb86a" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_CurrencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_ab64384d-2d1c-4bfd-ba5f-40990e21aa9d" xlink:to="loc_srt_CurrencyAxis_990bfda8-2229-4593-99f4-3afc4f3eb86a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_currency_AllCurrenciesDomain_990bfda8-2229-4593-99f4-3afc4f3eb86a_default" xlink:href="https://xbrl.sec.gov/currency/2021/currency-2021.xsd#currency_AllCurrenciesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CurrencyAxis_990bfda8-2229-4593-99f4-3afc4f3eb86a" xlink:to="loc_currency_AllCurrenciesDomain_990bfda8-2229-4593-99f4-3afc4f3eb86a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_currency_AllCurrenciesDomain_7a8eab6a-1cc7-4b5f-ad6b-af77f06dfde9" xlink:href="https://xbrl.sec.gov/currency/2021/currency-2021.xsd#currency_AllCurrenciesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CurrencyAxis_990bfda8-2229-4593-99f4-3afc4f3eb86a" xlink:to="loc_currency_AllCurrenciesDomain_7a8eab6a-1cc7-4b5f-ad6b-af77f06dfde9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_currency_JPY_3d002b0d-9d49-49c5-964e-01bab791c3fb" xlink:href="https://xbrl.sec.gov/currency/2021/currency-2021.xsd#currency_JPY"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_7a8eab6a-1cc7-4b5f-ad6b-af77f06dfde9" xlink:to="loc_currency_JPY_3d002b0d-9d49-49c5-964e-01bab791c3fb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_currency_KRW_7ddff775-088b-489e-b223-fccde5930849" xlink:href="https://xbrl.sec.gov/currency/2021/currency-2021.xsd#currency_KRW"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_7a8eab6a-1cc7-4b5f-ad6b-af77f06dfde9" xlink:to="loc_currency_KRW_7ddff775-088b-489e-b223-fccde5930849" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_currency_PHP_1d6a9074-b1ab-4c7a-b451-fe0a0cb6db87" xlink:href="https://xbrl.sec.gov/currency/2021/currency-2021.xsd#currency_PHP"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_7a8eab6a-1cc7-4b5f-ad6b-af77f06dfde9" xlink:to="loc_currency_PHP_1d6a9074-b1ab-4c7a-b451-fe0a0cb6db87" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_9bb14646-972f-44aa-9ba4-982e78155ce6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_ab64384d-2d1c-4bfd-ba5f-40990e21aa9d" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_9bb14646-972f-44aa-9ba4-982e78155ce6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_9bb14646-972f-44aa-9ba4-982e78155ce6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_9bb14646-972f-44aa-9ba4-982e78155ce6" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_9bb14646-972f-44aa-9ba4-982e78155ce6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_483d56b6-94e0-463f-8d1d-9d0eefa24ed9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_9bb14646-972f-44aa-9ba4-982e78155ce6" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_483d56b6-94e0-463f-8d1d-9d0eefa24ed9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentAssetsMember_23ef11ee-fe0b-49b3-b31a-c4445c5f239c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherCurrentAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_483d56b6-94e0-463f-8d1d-9d0eefa24ed9" xlink:to="loc_us-gaap_OtherCurrentAssetsMember_23ef11ee-fe0b-49b3-b31a-c4445c5f239c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_4fbf4002-dffb-402d-87b5-d5cc8200d1c6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_483d56b6-94e0-463f-8d1d-9d0eefa24ed9" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_4fbf4002-dffb-402d-87b5-d5cc8200d1c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_57b6dc43-6aef-42c2-bab0-e7e08fa8f242" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_ab64384d-2d1c-4bfd-ba5f-40990e21aa9d" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_57b6dc43-6aef-42c2-bab0-e7e08fa8f242" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_57b6dc43-6aef-42c2-bab0-e7e08fa8f242_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_57b6dc43-6aef-42c2-bab0-e7e08fa8f242" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_57b6dc43-6aef-42c2-bab0-e7e08fa8f242_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ce057f00-4c3e-4b9f-8de2-81beb3e27eef" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_57b6dc43-6aef-42c2-bab0-e7e08fa8f242" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ce057f00-4c3e-4b9f-8de2-81beb3e27eef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_7cbf3436-a22e-44a3-a7b3-a6d99ec8d3a1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ce057f00-4c3e-4b9f-8de2-81beb3e27eef" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_7cbf3436-a22e-44a3-a7b3-a6d99ec8d3a1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/FairValueMeasurementsDebtDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#FairValueMeasurementsDebtDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/FairValueMeasurementsDebtDetails" xlink:type="extended" id="i2e4f29625f73452ab8154c563c4492eb_FairValueMeasurementsDebtDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_4279b8fb-b03d-4006-b535-5668a58c7e19" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFairValue_1d7d179a-f0bf-4684-9713-704d696a4e54" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_4279b8fb-b03d-4006-b535-5668a58c7e19" xlink:to="loc_us-gaap_DebtInstrumentFairValue_1d7d179a-f0bf-4684-9713-704d696a4e54" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_42256ea2-be7a-4dd8-94e1-ca9211f743c8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_4279b8fb-b03d-4006-b535-5668a58c7e19" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_42256ea2-be7a-4dd8-94e1-ca9211f743c8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_273271db-9a21-4cbc-a05d-a4729f81256a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_42256ea2-be7a-4dd8-94e1-ca9211f743c8" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_273271db-9a21-4cbc-a05d-a4729f81256a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_273271db-9a21-4cbc-a05d-a4729f81256a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_273271db-9a21-4cbc-a05d-a4729f81256a" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_273271db-9a21-4cbc-a05d-a4729f81256a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2c5eeb56-c13f-4006-ac57-f6ada1d429e3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_273271db-9a21-4cbc-a05d-a4729f81256a" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2c5eeb56-c13f-4006-ac57-f6ada1d429e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_21df1377-0373-42d1-b018-bd9b006f8c2b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2c5eeb56-c13f-4006-ac57-f6ada1d429e3" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_21df1377-0373-42d1-b018-bd9b006f8c2b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_1ad2a760-9607-4cf2-b854-d0e62a9aafad" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2c5eeb56-c13f-4006-ac57-f6ada1d429e3" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_1ad2a760-9607-4cf2-b854-d0e62a9aafad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_b8ae076b-5ff1-4195-8750-f82077308f87" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2c5eeb56-c13f-4006-ac57-f6ada1d429e3" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_b8ae076b-5ff1-4195-8750-f82077308f87" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_c2d2043f-b3fa-4df6-9d96-c9783a7fa210" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_42256ea2-be7a-4dd8-94e1-ca9211f743c8" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_c2d2043f-b3fa-4df6-9d96-c9783a7fa210" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_c2d2043f-b3fa-4df6-9d96-c9783a7fa210_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_c2d2043f-b3fa-4df6-9d96-c9783a7fa210" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_c2d2043f-b3fa-4df6-9d96-c9783a7fa210_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_bc9c351d-0bae-4d6f-b8bb-9b1f864842d1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_c2d2043f-b3fa-4df6-9d96-c9783a7fa210" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_bc9c351d-0bae-4d6f-b8bb-9b1f864842d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_5cdc390c-9dd5-4f44-bc7b-240877ffd7d6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_bc9c351d-0bae-4d6f-b8bb-9b1f864842d1" xlink:to="loc_us-gaap_SeniorNotesMember_5cdc390c-9dd5-4f44-bc7b-240877ffd7d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SubsidiaryTermLoansandRevolvingCreditFacilitiesMember_9d523c59-dafe-47c4-ac23-53a93546cb48" xlink:href="amkr-20211231.xsd#amkr_SubsidiaryTermLoansandRevolvingCreditFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_bc9c351d-0bae-4d6f-b8bb-9b1f864842d1" xlink:to="loc_amkr_SubsidiaryTermLoansandRevolvingCreditFacilitiesMember_9d523c59-dafe-47c4-ac23-53a93546cb48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_8ed75a44-d5c8-4145-a63e-7004a6bbc4fc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_42256ea2-be7a-4dd8-94e1-ca9211f743c8" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_8ed75a44-d5c8-4145-a63e-7004a6bbc4fc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8ed75a44-d5c8-4145-a63e-7004a6bbc4fc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_8ed75a44-d5c8-4145-a63e-7004a6bbc4fc" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8ed75a44-d5c8-4145-a63e-7004a6bbc4fc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3a2958fb-caa2-4ba9-906e-e33ae82bc57e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_8ed75a44-d5c8-4145-a63e-7004a6bbc4fc" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3a2958fb-caa2-4ba9-906e-e33ae82bc57e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_029b4a4a-7d80-437b-aca3-a5fee245a5de" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3a2958fb-caa2-4ba9-906e-e33ae82bc57e" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_029b4a4a-7d80-437b-aca3-a5fee245a5de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_322c1f41-030d-4b55-be82-17fe62935256" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3a2958fb-caa2-4ba9-906e-e33ae82bc57e" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_322c1f41-030d-4b55-be82-17fe62935256" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/BusinessSegmentsCustomerConcentrationsandGeographicInformationDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#BusinessSegmentsCustomerConcentrationsandGeographicInformationDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/BusinessSegmentsCustomerConcentrationsandGeographicInformationDetails" xlink:type="extended" id="i5c84a68ea19d43c7ad1751b0daa30096_BusinessSegmentsCustomerConcentrationsandGeographicInformationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_ee3d2b3a-7a13-4a92-873e-01acf6c81686" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_e591f402-ba38-4964-8083-8ab1489ddf17" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ee3d2b3a-7a13-4a92-873e-01acf6c81686" xlink:to="loc_us-gaap_NumberOfOperatingSegments_e591f402-ba38-4964-8083-8ab1489ddf17" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_1d88b1c6-cd91-4ab0-bfd6-c443ecbba997" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ee3d2b3a-7a13-4a92-873e-01acf6c81686" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_1d88b1c6-cd91-4ab0-bfd6-c443ecbba997" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_f71c1971-3019-451a-97c9-3e1986699454" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ee3d2b3a-7a13-4a92-873e-01acf6c81686" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_f71c1971-3019-451a-97c9-3e1986699454" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_345685a4-0aec-46bc-a72d-54ac3c6aaa80" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ee3d2b3a-7a13-4a92-873e-01acf6c81686" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_345685a4-0aec-46bc-a72d-54ac3c6aaa80" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_4ec109cd-ae33-4382-ac0d-d6ad7606fd6b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ee3d2b3a-7a13-4a92-873e-01acf6c81686" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_4ec109cd-ae33-4382-ac0d-d6ad7606fd6b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f349d963-f1e8-475c-8a89-6b037520ea69" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ee3d2b3a-7a13-4a92-873e-01acf6c81686" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f349d963-f1e8-475c-8a89-6b037520ea69" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_b4e4227f-d3fe-425a-885d-040de7f1a9a0" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f349d963-f1e8-475c-8a89-6b037520ea69" xlink:to="loc_srt_ProductOrServiceAxis_b4e4227f-d3fe-425a-885d-040de7f1a9a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_b4e4227f-d3fe-425a-885d-040de7f1a9a0_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_b4e4227f-d3fe-425a-885d-040de7f1a9a0" xlink:to="loc_srt_ProductsAndServicesDomain_b4e4227f-d3fe-425a-885d-040de7f1a9a0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_985ebcee-00b8-486c-ac73-86f09443c77b" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_b4e4227f-d3fe-425a-885d-040de7f1a9a0" xlink:to="loc_srt_ProductsAndServicesDomain_985ebcee-00b8-486c-ac73-86f09443c77b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_AdvancedProductsMember_0c9a712c-8ba9-4c3f-9bd9-d8080633cdd2" xlink:href="amkr-20211231.xsd#amkr_AdvancedProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_985ebcee-00b8-486c-ac73-86f09443c77b" xlink:to="loc_amkr_AdvancedProductsMember_0c9a712c-8ba9-4c3f-9bd9-d8080633cdd2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_MainstreamProductsMember_be1a5b81-acc6-4aa7-bec0-4c544da4deb6" xlink:href="amkr-20211231.xsd#amkr_MainstreamProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_985ebcee-00b8-486c-ac73-86f09443c77b" xlink:to="loc_amkr_MainstreamProductsMember_be1a5b81-acc6-4aa7-bec0-4c544da4deb6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SalesChannelCommunicationsMember_f31d7bb3-f703-416a-9885-0538453933b7" xlink:href="amkr-20211231.xsd#amkr_SalesChannelCommunicationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_985ebcee-00b8-486c-ac73-86f09443c77b" xlink:to="loc_amkr_SalesChannelCommunicationsMember_f31d7bb3-f703-416a-9885-0538453933b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SalesChannelConsumerGoodsMember_e52f2cbc-1937-432b-b8c1-2f349ca0ebc2" xlink:href="amkr-20211231.xsd#amkr_SalesChannelConsumerGoodsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_985ebcee-00b8-486c-ac73-86f09443c77b" xlink:to="loc_amkr_SalesChannelConsumerGoodsMember_e52f2cbc-1937-432b-b8c1-2f349ca0ebc2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SalesChannelAutomotiveIndustrialAndOtherMember_ad94d85c-f954-4d70-8a42-5ae0a4c5b68f" xlink:href="amkr-20211231.xsd#amkr_SalesChannelAutomotiveIndustrialAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_985ebcee-00b8-486c-ac73-86f09443c77b" xlink:to="loc_amkr_SalesChannelAutomotiveIndustrialAndOtherMember_ad94d85c-f954-4d70-8a42-5ae0a4c5b68f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_SalesChannelComputingMember_66a67056-86d7-4a22-a724-48346582b99a" xlink:href="amkr-20211231.xsd#amkr_SalesChannelComputingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_985ebcee-00b8-486c-ac73-86f09443c77b" xlink:to="loc_amkr_SalesChannelComputingMember_66a67056-86d7-4a22-a724-48346582b99a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_b4efa425-3cd0-429d-8c32-e7272d10f139" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f349d963-f1e8-475c-8a89-6b037520ea69" xlink:to="loc_srt_MajorCustomersAxis_b4efa425-3cd0-429d-8c32-e7272d10f139" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_b4efa425-3cd0-429d-8c32-e7272d10f139_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_b4efa425-3cd0-429d-8c32-e7272d10f139" xlink:to="loc_srt_NameOfMajorCustomerDomain_b4efa425-3cd0-429d-8c32-e7272d10f139_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_78bc74f5-0110-48e0-b7bd-b7ec49610173" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_b4efa425-3cd0-429d-8c32-e7272d10f139" xlink:to="loc_srt_NameOfMajorCustomerDomain_78bc74f5-0110-48e0-b7bd-b7ec49610173" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_CustomerOneMember_9ebeef38-eff6-427c-b261-91084817020e" xlink:href="amkr-20211231.xsd#amkr_CustomerOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_78bc74f5-0110-48e0-b7bd-b7ec49610173" xlink:to="loc_amkr_CustomerOneMember_9ebeef38-eff6-427c-b261-91084817020e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_9181bad4-3f26-4ea3-b025-46f258440a13" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f349d963-f1e8-475c-8a89-6b037520ea69" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_9181bad4-3f26-4ea3-b025-46f258440a13" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_9181bad4-3f26-4ea3-b025-46f258440a13_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_9181bad4-3f26-4ea3-b025-46f258440a13" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_9181bad4-3f26-4ea3-b025-46f258440a13_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a097ad0a-b569-4f0e-839b-ff792255bb9a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_9181bad4-3f26-4ea3-b025-46f258440a13" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a097ad0a-b569-4f0e-839b-ff792255bb9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesMember_301136a4-28c1-47cf-b348-2ab015fee31f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a097ad0a-b569-4f0e-839b-ff792255bb9a" xlink:to="loc_us-gaap_SalesMember_301136a4-28c1-47cf-b348-2ab015fee31f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_ee95c23f-b2f0-4e4f-8ad2-c9191ebe56be" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f349d963-f1e8-475c-8a89-6b037520ea69" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_ee95c23f-b2f0-4e4f-8ad2-c9191ebe56be" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_ee95c23f-b2f0-4e4f-8ad2-c9191ebe56be_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_ee95c23f-b2f0-4e4f-8ad2-c9191ebe56be" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_ee95c23f-b2f0-4e4f-8ad2-c9191ebe56be_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_c6df5b47-c9ca-4207-8884-bc5e80aec1f3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_ee95c23f-b2f0-4e4f-8ad2-c9191ebe56be" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_c6df5b47-c9ca-4207-8884-bc5e80aec1f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductConcentrationRiskMember_fe14e67a-4ce7-4c09-b013-9741e2b123d6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProductConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_c6df5b47-c9ca-4207-8884-bc5e80aec1f3" xlink:to="loc_us-gaap_ProductConcentrationRiskMember_fe14e67a-4ce7-4c09-b013-9741e2b123d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_1267df7f-7f68-4ba9-99c1-833680b4812d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_c6df5b47-c9ca-4207-8884-bc5e80aec1f3" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_1267df7f-7f68-4ba9-99c1-833680b4812d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_fe10e7c8-5f0e-448c-b9b3-af1962ae7459" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f349d963-f1e8-475c-8a89-6b037520ea69" xlink:to="loc_srt_StatementGeographicalAxis_fe10e7c8-5f0e-448c-b9b3-af1962ae7459" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_fe10e7c8-5f0e-448c-b9b3-af1962ae7459_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_fe10e7c8-5f0e-448c-b9b3-af1962ae7459" xlink:to="loc_srt_SegmentGeographicalDomain_fe10e7c8-5f0e-448c-b9b3-af1962ae7459_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_fe10e7c8-5f0e-448c-b9b3-af1962ae7459" xlink:to="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_JP_b10f4b5c-9d7e-4e54-95d7-3597d2677535" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_JP"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_country_JP_b10f4b5c-9d7e-4e54-95d7-3597d2677535" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_51c897ca-e722-4819-b829-9a519209ac0b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_us-gaap_EMEAMember_51c897ca-e722-4819-b829-9a519209ac0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaMember_8d577002-b4ae-4a7a-bb55-f944e762ffee" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_AsiaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_srt_AsiaMember_8d577002-b4ae-4a7a-bb55-f944e762ffee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_fc13f96f-2659-44df-a35c-4b7040bf3258" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_us-gaap_NonUsMember_fc13f96f-2659-44df-a35c-4b7040bf3258" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_ccc078a2-8fcd-4388-958e-f70bef124db5" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_country_US_ccc078a2-8fcd-4388-958e-f70bef124db5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_1f8ead2c-9e03-4ac3-a0f3-8846c0186288" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_country_CN_1f8ead2c-9e03-4ac3-a0f3-8846c0186288" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_KR_93210ba2-03fe-4d69-afc1-9da09616908f" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_KR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_country_KR_93210ba2-03fe-4d69-afc1-9da09616908f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_MY_8f7a5e12-be46-424f-947c-007d2884db97" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_MY"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_country_MY_8f7a5e12-be46-424f-947c-007d2884db97" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_PH_570a2bce-656e-4d6a-b5de-dbef52e36592" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_PH"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_country_PH_570a2bce-656e-4d6a-b5de-dbef52e36592" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_PT_cb883b31-b5d5-497a-b25f-b1cb97e6256d" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_PT"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_country_PT_cb883b31-b5d5-497a-b25f-b1cb97e6256d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_TW_b47607f6-9ec1-425b-b7e2-6057a1ebc145" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_TW"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_country_TW_b47607f6-9ec1-425b-b7e2-6057a1ebc145" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_OtherForeignCountriesMember_eb17abdf-f35a-40b3-93ee-08c98aa04b2b" xlink:href="amkr-20211231.xsd#amkr_OtherForeignCountriesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3fe2cff4-a0b9-438c-a47b-89be5636ef15" xlink:to="loc_amkr_OtherForeignCountriesMember_eb17abdf-f35a-40b3-93ee-08c98aa04b2b" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/RestructuringandRelatedActivitiesDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#RestructuringandRelatedActivitiesDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/RestructuringandRelatedActivitiesDetails" xlink:type="extended" id="i129e6429657a4553bd1aa842dacfb9e1_RestructuringandRelatedActivitiesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_6687073f-c4bc-4fae-b383-1b5098b312e5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveRollForward_87fd947c-6078-44fd-a61b-bcab8aa4c644" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringReserveRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_6687073f-c4bc-4fae-b383-1b5098b312e5" xlink:to="loc_us-gaap_RestructuringReserveRollForward_87fd947c-6078-44fd-a61b-bcab8aa4c644" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_fb2926b6-9921-4a7c-98ec-3f3b67f1aa07" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringReserve"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_87fd947c-6078-44fd-a61b-bcab8aa4c644" xlink:to="loc_us-gaap_RestructuringReserve_fb2926b6-9921-4a7c-98ec-3f3b67f1aa07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_39653d95-d14d-4979-b971-91c2725516d7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_87fd947c-6078-44fd-a61b-bcab8aa4c644" xlink:to="loc_us-gaap_RestructuringCharges_39653d95-d14d-4979-b971-91c2725516d7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRestructuring_9a0380d7-4360-4393-8a67-55b6cc7040e3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsForRestructuring"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_87fd947c-6078-44fd-a61b-bcab8aa4c644" xlink:to="loc_us-gaap_PaymentsForRestructuring_9a0380d7-4360-4393-8a67-55b6cc7040e3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveTranslationAndOtherAdjustment_54c7ca91-d7cf-4d16-9ad8-373c9be1c5a6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringReserveTranslationAndOtherAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_87fd947c-6078-44fd-a61b-bcab8aa4c644" xlink:to="loc_us-gaap_RestructuringReserveTranslationAndOtherAdjustment_54c7ca91-d7cf-4d16-9ad8-373c9be1c5a6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_a93626fd-53fe-43d3-918a-243c1fcb9454" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringReserve"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostCostIncurredToDate1_7daf9f9e-ef7d-4000-ae65-ad53bb0f0d9b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringAndRelatedCostCostIncurredToDate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_6687073f-c4bc-4fae-b383-1b5098b312e5" xlink:to="loc_us-gaap_RestructuringAndRelatedCostCostIncurredToDate1_7daf9f9e-ef7d-4000-ae65-ad53bb0f0d9b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1_1e64d86a-cbba-4986-b821-8a238a7b5254" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_6687073f-c4bc-4fae-b383-1b5098b312e5" xlink:to="loc_us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1_1e64d86a-cbba-4986-b821-8a238a7b5254" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_b603869b-8537-4e17-aba7-7cc5b3eba136" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_6687073f-c4bc-4fae-b383-1b5098b312e5" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_b603869b-8537-4e17-aba7-7cc5b3eba136" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_7cdb70a3-5143-4e82-98e1-784e1887a4bd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_b603869b-8537-4e17-aba7-7cc5b3eba136" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_7cdb70a3-5143-4e82-98e1-784e1887a4bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_7cdb70a3-5143-4e82-98e1-784e1887a4bd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_7cdb70a3-5143-4e82-98e1-784e1887a4bd" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_7cdb70a3-5143-4e82-98e1-784e1887a4bd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_c7a4d704-9aee-492a-864e-960f8d79de51" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_7cdb70a3-5143-4e82-98e1-784e1887a4bd" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_c7a4d704-9aee-492a-864e-960f8d79de51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FacilityClosingMember_6237a573-e907-493a-8b36-d777bfa4bebb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FacilityClosingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_c7a4d704-9aee-492a-864e-960f8d79de51" xlink:to="loc_us-gaap_FacilityClosingMember_6237a573-e907-493a-8b36-d777bfa4bebb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeSeveranceMember_7582e643-cea7-4d56-92a4-7faa714474c0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeSeveranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_c7a4d704-9aee-492a-864e-960f8d79de51" xlink:to="loc_us-gaap_EmployeeSeveranceMember_7582e643-cea7-4d56-92a4-7faa714474c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherRestructuringMember_6a13d605-3e2b-4af4-845d-ef72ad369f4c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherRestructuringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_c7a4d704-9aee-492a-864e-960f8d79de51" xlink:to="loc_us-gaap_OtherRestructuringMember_6a13d605-3e2b-4af4-845d-ef72ad369f4c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanAxis_5bb23a72-f556-4a35-8a68-1645c6b5958d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringPlanAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_b603869b-8537-4e17-aba7-7cc5b3eba136" xlink:to="loc_us-gaap_RestructuringPlanAxis_5bb23a72-f556-4a35-8a68-1645c6b5958d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_5bb23a72-f556-4a35-8a68-1645c6b5958d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_5bb23a72-f556-4a35-8a68-1645c6b5958d" xlink:to="loc_us-gaap_RestructuringPlanDomain_5bb23a72-f556-4a35-8a68-1645c6b5958d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_394fb5cb-fce4-457e-82d3-b03b71c0ada5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_5bb23a72-f556-4a35-8a68-1645c6b5958d" xlink:to="loc_us-gaap_RestructuringPlanDomain_394fb5cb-fce4-457e-82d3-b03b71c0ada5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_amkr_JapanConsolidationActivitiesMember_016ce272-5eba-4376-b20f-99205bf01ba5" xlink:href="amkr-20211231.xsd#amkr_JapanConsolidationActivitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_394fb5cb-fce4-457e-82d3-b03b71c0ada5" xlink:to="loc_amkr_JapanConsolidationActivitiesMember_016ce272-5eba-4376-b20f-99205bf01ba5" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.amkor.com/role/ScheduleIIValuationandQualifyingAccountsDetails" xlink:type="simple" xlink:href="amkr-20211231.xsd#ScheduleIIValuationandQualifyingAccountsDetails"/>
  <link:definitionLink xlink:role="http://www.amkor.com/role/ScheduleIIValuationandQualifyingAccountsDetails" xlink:type="extended" id="i42dd33af99584e778a42f90e1e76c74c_ScheduleIIValuationandQualifyingAccountsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_b5c16c8b-e856-4f8a-8f1b-ba91c927d7bc" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_91fdde02-e82a-47b1-ac43-67cca48ad018" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MovementInValuationAllowancesAndReservesRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_b5c16c8b-e856-4f8a-8f1b-ba91c927d7bc" xlink:to="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_91fdde02-e82a-47b1-ac43-67cca48ad018" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_aff5ecf3-c7cd-4b09-8a21-9ae71b57e838" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_91fdde02-e82a-47b1-ac43-67cca48ad018" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_aff5ecf3-c7cd-4b09-8a21-9ae71b57e838" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_3396ba2a-fbbb-4e7b-9c58-bba86a94e087" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_91fdde02-e82a-47b1-ac43-67cca48ad018" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_3396ba2a-fbbb-4e7b-9c58-bba86a94e087" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions_729c22b0-ca3d-4194-8e69-9762d21e8a01" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_91fdde02-e82a-47b1-ac43-67cca48ad018" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDeductions_729c22b0-ca3d-4194-8e69-9762d21e8a01" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_6a620d8f-223d-425b-b41f-9296d20227f0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_5e5d31f2-ea4f-47ad-9c2e-e56df5c9e3ce" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_b5c16c8b-e856-4f8a-8f1b-ba91c927d7bc" xlink:to="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_5e5d31f2-ea4f-47ad-9c2e-e56df5c9e3ce" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_1e0204a3-be98-428f-a2c0-dee19b608f2a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_5e5d31f2-ea4f-47ad-9c2e-e56df5c9e3ce" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_1e0204a3-be98-428f-a2c0-dee19b608f2a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_1e0204a3-be98-428f-a2c0-dee19b608f2a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_1e0204a3-be98-428f-a2c0-dee19b608f2a" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_1e0204a3-be98-428f-a2c0-dee19b608f2a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_e0838eb5-1657-448f-9f5d-90fb9419cd13" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_1e0204a3-be98-428f-a2c0-dee19b608f2a" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_e0838eb5-1657-448f-9f5d-90fb9419cd13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_92e96867-0e12-4bfb-8498-fd11af022c7a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_e0838eb5-1657-448f-9f5d-90fb9419cd13" xlink:to="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_92e96867-0e12-4bfb-8498-fd11af022c7a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-roles-2021-01-31.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
