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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e8a0f-4035-7d66-905d-8617c2a9f493,g:044cd2ba-e111-4732-8195-53c11fd54525-->
<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.logitech.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCHANGESINSHAREHOLDERSEQUITY" xlink:type="simple" xlink:href="logi-20260630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCHANGESINSHAREHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCHANGESINSHAREHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019e8a0f-4101-795d-9320-fa14d12b9e14" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019e8a0f-4101-74dc-a0a4-7d34a79ee8c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019e8a0f-4101-795d-9320-fa14d12b9e14" xlink:to="loc_us-gaap_StatementTable_019e8a0f-4101-74dc-a0a4-7d34a79ee8c7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-4101-70b0-a9b3-947c7e2c4480" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019e8a0f-4101-74dc-a0a4-7d34a79ee8c7" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-4101-70b0-a9b3-947c7e2c4480" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e8a0f-4101-70b0-a9b3-947c7e2c4480_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-4101-70b0-a9b3-947c7e2c4480" xlink:to="loc_us-gaap_EquityComponentDomain_019e8a0f-4101-70b0-a9b3-947c7e2c4480_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e8a0f-4101-7515-95e1-1f9283b4cfc3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-4101-70b0-a9b3-947c7e2c4480" xlink:to="loc_us-gaap_EquityComponentDomain_019e8a0f-4101-7515-95e1-1f9283b4cfc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019e8a0f-4101-7435-9746-9df0f9b89b1a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8a0f-4101-7515-95e1-1f9283b4cfc3" xlink:to="loc_us-gaap_CommonStockMember_019e8a0f-4101-7435-9746-9df0f9b89b1a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019e8a0f-4101-7fb5-be14-eb61a1ea92fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8a0f-4101-7515-95e1-1f9283b4cfc3" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019e8a0f-4101-7fb5-be14-eb61a1ea92fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_019e8a0f-4101-7056-85c4-e224874b8a80" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8a0f-4101-7515-95e1-1f9283b4cfc3" xlink:to="loc_us-gaap_TreasuryStockCommonMember_019e8a0f-4101-7056-85c4-e224874b8a80" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019e8a0f-4101-710e-9e34-857c6afd385b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8a0f-4101-7515-95e1-1f9283b4cfc3" xlink:to="loc_us-gaap_RetainedEarningsMember_019e8a0f-4101-710e-9e34-857c6afd385b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e8a0f-4101-77c0-b128-00b8c594b5eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8a0f-4101-7515-95e1-1f9283b4cfc3" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e8a0f-4101-77c0-b128-00b8c594b5eb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e8a0f-4101-795d-9320-fa14d12b9e14" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019e8a0f-4101-7031-8413-adee6238a409" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019e8a0f-4101-7031-8413-adee6238a409" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e8a0f-4101-7846-b150-b7d74ae82cd1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_us-gaap_StockholdersEquity_019e8a0f-4101-7846-b150-b7d74ae82cd1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019e8a0f-4101-7285-91b3-1c96467bc224" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_us-gaap_TreasuryStockCommonShares_019e8a0f-4101-7285-91b3-1c96467bc224" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019e8a0f-4101-7087-b71d-3894d3c83e74" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_019e8a0f-4101-7087-b71d-3894d3c83e74" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_019e8a0f-4101-7bdd-9958-b7cdebe289f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_019e8a0f-4101-7bdd-9958-b7cdebe289f3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_019e8a0f-4101-7adb-b60e-70a427929be2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_019e8a0f-4101-7adb-b60e-70a427929be2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_SaleOfSharesUponExerciseOfOptionAndPurchaseRight_019e8a0f-4101-7d03-9a66-338c3187fdcf" xlink:href="logi-20260630.xsd#logi_SaleOfSharesUponExerciseOfOptionAndPurchaseRight"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_logi_SaleOfSharesUponExerciseOfOptionAndPurchaseRight_019e8a0f-4101-7d03-9a66-338c3187fdcf" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_SaleOfSharesUponExerciseOfOptionAndPurchaseRightShares_019e8a0f-4101-7647-8ac2-6b3bf0a9cd7b" xlink:href="logi-20260630.xsd#logi_SaleOfSharesUponExerciseOfOptionAndPurchaseRightShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_logi_SaleOfSharesUponExerciseOfOptionAndPurchaseRightShares_019e8a0f-4101-7647-8ac2-6b3bf0a9cd7b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_StockIssuedDuringPeriodValueRestrictedStockAwardVested_019e8a0f-4101-781f-bc25-f442c927c287" xlink:href="logi-20260630.xsd#logi_StockIssuedDuringPeriodValueRestrictedStockAwardVested"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_logi_StockIssuedDuringPeriodValueRestrictedStockAwardVested_019e8a0f-4101-781f-bc25-f442c927c287" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_StockIssuedDuringPeriodSharesRestrictedStockAwardVested_019e8a0f-4101-7f34-8d99-5ec6353bdc1f" xlink:href="logi-20260630.xsd#logi_StockIssuedDuringPeriodSharesRestrictedStockAwardVested"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_logi_StockIssuedDuringPeriodSharesRestrictedStockAwardVested_019e8a0f-4101-7f34-8d99-5ec6353bdc1f" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019e8a0f-4101-740c-8cb9-5d04ae18f149" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8a0f-4101-72ba-b273-1170334be93c" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019e8a0f-4101-740c-8cb9-5d04ae18f149" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019f8032-8586-7f87-925d-cf292dfae5a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e8a0f-4101-7bba-9d76-f7c41ffa97ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019e8a0f-4101-73c1-8465-2c4a11fddbfe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/TheCompanyandSummaryofSignificantAccountingPoliciesandEstimatesDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#TheCompanyandSummaryofSignificantAccountingPoliciesandEstimatesDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/TheCompanyandSummaryofSignificantAccountingPoliciesandEstimatesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementLineItems_019f6540-002c-7de9-acc2-5821c4bc3cd5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable_019f6540-002c-708a-8703-d3ee44913ce7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementLineItems_019f6540-002c-7de9-acc2-5821c4bc3cd5" xlink:to="loc_us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable_019f6540-002c-708a-8703-d3ee44913ce7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019f6540-002c-7ce6-9ab4-0c65cb51c2cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable_019f6540-002c-708a-8703-d3ee44913ce7" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019f6540-002c-7ce6-9ab4-0c65cb51c2cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019f6540-002c-7ce6-9ab4-0c65cb51c2cb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019f6540-002c-7ce6-9ab4-0c65cb51c2cb" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019f6540-002c-7ce6-9ab4-0c65cb51c2cb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019f6540-002c-7411-ac3e-a7b0205fc0cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019f6540-002c-7ce6-9ab4-0c65cb51c2cb" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019f6540-002c-7411-ac3e-a7b0205fc0cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019f6540-002c-7432-b30b-3d67e76f76cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019f6540-002c-7411-ac3e-a7b0205fc0cb" xlink:to="loc_us-gaap_SubsequentEventMember_019f6540-002c-7432-b30b-3d67e76f76cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainContingenciesByNatureAxis_019f8029-54df-7a71-8c8b-b195d9a3a981" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainContingenciesByNatureAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfErrorCorrectionsAndPriorPeriodAdjustmentRestatementTable_019f6540-002c-708a-8703-d3ee44913ce7" xlink:to="loc_us-gaap_GainContingenciesByNatureAxis_019f8029-54df-7a71-8c8b-b195d9a3a981" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainContingencyNatureDomain_019f8029-54df-7a71-8c8b-b195d9a3a981_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GainContingenciesByNatureAxis_019f8029-54df-7a71-8c8b-b195d9a3a981" xlink:to="loc_us-gaap_GainContingencyNatureDomain_019f8029-54df-7a71-8c8b-b195d9a3a981_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainContingencyNatureDomain_019f8029-54df-7a51-a4b2-1e8861bb4982" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GainContingenciesByNatureAxis_019f8029-54df-7a71-8c8b-b195d9a3a981" xlink:to="loc_us-gaap_GainContingencyNatureDomain_019f8029-54df-7a51-a4b2-1e8861bb4982" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_IEEPATariffRefundMember_019f8029-dcbe-7c18-8c6c-29cf8e1d94b2" xlink:href="logi-20260630.xsd#logi_IEEPATariffRefundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingencyNatureDomain_019f8029-54df-7a51-a4b2-1e8861bb4982" xlink:to="loc_logi_IEEPATariffRefundMember_019f8029-dcbe-7c18-8c6c-29cf8e1d94b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RecoveryOfDirectCosts_019f8026-c437-7958-bb48-b83fe18c2842" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RecoveryOfDirectCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementLineItems_019f6540-002c-7de9-acc2-5821c4bc3cd5" xlink:to="loc_us-gaap_RecoveryOfDirectCosts_019f8026-c437-7958-bb48-b83fe18c2842" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableForRecoveryOfImportDutiesNet_019f8092-7293-7015-9fbd-bb9ec577fe76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivableForRecoveryOfImportDutiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementLineItems_019f6540-002c-7de9-acc2-5821c4bc3cd5" xlink:to="loc_us-gaap_ReceivableForRecoveryOfImportDutiesNet_019f8092-7293-7015-9fbd-bb9ec577fe76" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/EmployeeBenefitPlansScheduleofSharebasedCompensationExpensesandRelatedTaxBenefitsRecognizedDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#EmployeeBenefitPlansScheduleofSharebasedCompensationExpensesandRelatedTaxBenefitsRecognizedDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/EmployeeBenefitPlansScheduleofSharebasedCompensationExpensesandRelatedTaxBenefitsRecognizedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8a0f-4102-75e2-bfd2-8185a605dcca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e8a0f-4102-72d7-9bb1-c53290f26932" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8a0f-4102-75e2-bfd2-8185a605dcca" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e8a0f-4102-72d7-9bb1-c53290f26932" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019e8a0f-4102-71bd-b74c-19414e38fc14" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e8a0f-4102-72d7-9bb1-c53290f26932" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019e8a0f-4102-71bd-b74c-19414e38fc14" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e8a0f-4102-76aa-a630-e932cdb033a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8a0f-4102-75e2-bfd2-8185a605dcca" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e8a0f-4102-76aa-a630-e932cdb033a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_019e8a0f-4102-7a6d-b40b-1d4077f853db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8a0f-4102-75e2-bfd2-8185a605dcca" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_019e8a0f-4102-7a6d-b40b-1d4077f853db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_019e8a0f-4102-7d2c-9fe6-c49714171669" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8a0f-4102-75e2-bfd2-8185a605dcca" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_019e8a0f-4102-7d2c-9fe6-c49714171669" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/EmployeeBenefitPlansScheduleofSharebasedCompensationExpensesandRelatedTaxBenefitsRecognizedDetails_1" xlink:type="simple" xlink:href="logi-20260630.xsd#EmployeeBenefitPlansScheduleofSharebasedCompensationExpensesandRelatedTaxBenefitsRecognizedDetails_1"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/EmployeeBenefitPlansScheduleofSharebasedCompensationExpensesandRelatedTaxBenefitsRecognizedDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8a0f-4102-75e2-bfd2-8185a605dcca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e8a0f-4102-72d7-9bb1-c53290f26932" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8a0f-4102-75e2-bfd2-8185a605dcca" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e8a0f-4102-72d7-9bb1-c53290f26932" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e8a0f-4102-76aa-a630-e932cdb033a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8a0f-4102-75e2-bfd2-8185a605dcca" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e8a0f-4102-76aa-a630-e932cdb033a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_019e8a0f-4102-7a6d-b40b-1d4077f853db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8a0f-4102-75e2-bfd2-8185a605dcca" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_019e8a0f-4102-7a6d-b40b-1d4077f853db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_019e8a0f-4102-7d2c-9fe6-c49714171669" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8a0f-4102-75e2-bfd2-8185a605dcca" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_019e8a0f-4102-7d2c-9fe6-c49714171669" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/BalanceSheetComponentsScheduleofComponentsofCertainBalanceSheetAssetAmountsDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#BalanceSheetComponentsScheduleofComponentsofCertainBalanceSheetAssetAmountsDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/BalanceSheetComponentsScheduleofComponentsofCertainBalanceSheetAssetAmountsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019e8a0f-41c8-7250-b9e4-60b64d3b1bd0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019e8a0f-41c8-74cd-8b8d-837649fce717" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019e8a0f-41c8-7250-b9e4-60b64d3b1bd0" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019e8a0f-41c8-74cd-8b8d-837649fce717" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_019e8a0f-41c8-769a-9a23-d5107df8e079" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019e8a0f-41c8-74cd-8b8d-837649fce717" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_019e8a0f-41c8-769a-9a23-d5107df8e079" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_019e8a0f-41c8-769a-9a23-d5107df8e079_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_019e8a0f-41c8-769a-9a23-d5107df8e079" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_019e8a0f-41c8-769a-9a23-d5107df8e079_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_019e8a0f-41c8-7f74-b48b-790e40eec2d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_019e8a0f-41c8-769a-9a23-d5107df8e079" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_019e8a0f-41c8-7f74-b48b-790e40eec2d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_AllowanceForCooperativeMarketingArrangementsMember_019e8a0f-41c8-7431-bbaa-a5191dd548da" xlink:href="logi-20260630.xsd#logi_AllowanceForCooperativeMarketingArrangementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_019e8a0f-41c8-7f74-b48b-790e40eec2d6" xlink:to="loc_logi_AllowanceForCooperativeMarketingArrangementsMember_019e8a0f-41c8-7431-bbaa-a5191dd548da" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_AllowanceForCustomerIncentiveProgramsMember_019e8a0f-41c8-7afa-9015-40f958388c1e" xlink:href="logi-20260630.xsd#logi_AllowanceForCustomerIncentiveProgramsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_019e8a0f-41c8-7f74-b48b-790e40eec2d6" xlink:to="loc_logi_AllowanceForCustomerIncentiveProgramsMember_019e8a0f-41c8-7afa-9015-40f958388c1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_AllowanceForPricingProgramsMember_019e8a0f-41c8-7ae3-b0f5-1feead141a46" xlink:href="logi-20260630.xsd#logi_AllowanceForPricingProgramsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_019e8a0f-41c8-7f74-b48b-790e40eec2d6" xlink:to="loc_logi_AllowanceForPricingProgramsMember_019e8a0f-41c8-7ae3-b0f5-1feead141a46" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_OtherAllowancesMember_019e8a0f-41c8-7aba-8294-dfccc4e87033" xlink:href="logi-20260630.xsd#logi_OtherAllowancesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_019e8a0f-41c8-7f74-b48b-790e40eec2d6" xlink:to="loc_logi_OtherAllowancesMember_019e8a0f-41c8-7aba-8294-dfccc4e87033" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis_019e8a0f-41c8-7183-8b0c-413db2188707" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019e8a0f-41c8-74cd-8b8d-837649fce717" xlink:to="loc_us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis_019e8a0f-41c8-7183-8b0c-413db2188707" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_019e8a0f-41c8-7183-8b0c-413db2188707_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis_019e8a0f-41c8-7183-8b0c-413db2188707" xlink:to="loc_us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_019e8a0f-41c8-7183-8b0c-413db2188707_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_019e8a0f-41c8-7000-8495-e94a968e27d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis_019e8a0f-41c8-7183-8b0c-413db2188707" xlink:to="loc_us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_019e8a0f-41c8-7000-8495-e94a968e27d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationExcludingShareBasedPaymentsAndRetirementBenefitsMember_019e8a0f-41c8-7368-b6da-c507ab68bc46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredCompensationExcludingShareBasedPaymentsAndRetirementBenefitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_019e8a0f-41c8-7000-8495-e94a968e27d5" xlink:to="loc_us-gaap_DeferredCompensationExcludingShareBasedPaymentsAndRetirementBenefitsMember_019e8a0f-41c8-7368-b6da-c507ab68bc46" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrentAbstract_019e8a0f-41c8-71c4-ae7e-ae8067821794" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019e8a0f-41c8-7250-b9e4-60b64d3b1bd0" xlink:to="loc_us-gaap_AccountsReceivableNetCurrentAbstract_019e8a0f-41c8-71c4-ae7e-ae8067821794" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableGrossCurrent_019e8a0f-41c8-71a8-b795-f404436e5331" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableGrossCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsReceivableNetCurrentAbstract_019e8a0f-41c8-71c4-ae7e-ae8067821794" xlink:to="loc_us-gaap_AccountsReceivableGrossCurrent_019e8a0f-41c8-71a8-b795-f404436e5331" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_019e8a0f-41c8-7e93-a4e8-3b06bbc85647" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsReceivableNetCurrentAbstract_019e8a0f-41c8-71c4-ae7e-ae8067821794" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_019e8a0f-41c8-7e93-a4e8-3b06bbc85647" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019e8a0f-41c8-7509-9ac2-7c3b923e6fb5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsReceivableNetCurrentAbstract_019e8a0f-41c8-71c4-ae7e-ae8067821794" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019e8a0f-41c8-7509-9ac2-7c3b923e6fb5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNetAbstract_019e8a0f-41c8-73d5-ad01-09e1e13b3db6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019e8a0f-41c8-7250-b9e4-60b64d3b1bd0" xlink:to="loc_us-gaap_InventoryNetAbstract_019e8a0f-41c8-73d5-ad01-09e1e13b3db6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryRawMaterialsNetOfReserves_019e8a0f-41c8-7a53-bf8d-6526d5c82caa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryRawMaterialsNetOfReserves"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_019e8a0f-41c8-73d5-ad01-09e1e13b3db6" xlink:to="loc_us-gaap_InventoryRawMaterialsNetOfReserves_019e8a0f-41c8-7a53-bf8d-6526d5c82caa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_019e8a0f-41c8-7aff-9be6-362b2dce97fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_019e8a0f-41c8-73d5-ad01-09e1e13b3db6" xlink:to="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_019e8a0f-41c8-7aff-9be6-362b2dce97fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_019e8a0f-41c8-7d14-a3bf-5175f439b171" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryNetAbstract_019e8a0f-41c8-73d5-ad01-09e1e13b3db6" xlink:to="loc_us-gaap_InventoryNet_019e8a0f-41c8-7d14-a3bf-5175f439b171" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract_019e8a0f-41c8-7d83-8777-8c75b1e5e3a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019e8a0f-41c8-7250-b9e4-60b64d3b1bd0" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract_019e8a0f-41c8-7d83-8777-8c75b1e5e3a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValueAddedTaxReceivable_019e8a0f-41c8-78e9-9bb0-88ba4c4e65d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValueAddedTaxReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract_019e8a0f-41c8-7d83-8777-8c75b1e5e3a8" xlink:to="loc_us-gaap_ValueAddedTaxReceivable_019e8a0f-41c8-78e9-9bb0-88ba4c4e65d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019e8a0f-41c8-7982-b7a3-a5d7db391681" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract_019e8a0f-41c8-7d83-8777-8c75b1e5e3a8" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019e8a0f-41c8-7982-b7a3-a5d7db391681" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent_019e8a0f-41c8-74f2-89fe-7a213a43dcf0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract_019e8a0f-41c8-7d83-8777-8c75b1e5e3a8" xlink:to="loc_us-gaap_OtherAssetsCurrent_019e8a0f-41c8-74f2-89fe-7a213a43dcf0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAbstract_019e8a0f-41c8-74f9-bb03-6656fb0af8c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019e8a0f-41c8-7250-b9e4-60b64d3b1bd0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAbstract_019e8a0f-41c8-74f9-bb03-6656fb0af8c4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019e8a0f-41c8-71ee-a33f-43ced6daf3c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAbstract_019e8a0f-41c8-74f9-bb03-6656fb0af8c4" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019e8a0f-41c8-71ee-a33f-43ced6daf3c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019e8a0f-41c8-78e7-ab29-92ed9bf742e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAbstract_019e8a0f-41c8-74f9-bb03-6656fb0af8c4" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019e8a0f-41c8-78e7-ab29-92ed9bf742e3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019e8a0f-41c8-71b4-ab05-532036e765ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAbstract_019e8a0f-41c8-74f9-bb03-6656fb0af8c4" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019e8a0f-41c8-71b4-ab05-532036e765ec" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrentAbstract_019e8a0f-41c8-7933-9bd9-d2b82a62156b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsNoncurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019e8a0f-41c8-7250-b9e4-60b64d3b1bd0" xlink:to="loc_us-gaap_OtherAssetsNoncurrentAbstract_019e8a0f-41c8-7933-9bd9-d2b82a62156b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_019e8a0f-41c8-7665-a8c5-28ba4e16efab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_019e8a0f-41c8-7933-9bd9-d2b82a62156b" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_019e8a0f-41c8-7665-a8c5-28ba4e16efab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019e8a0f-41c8-718a-86de-5b537f88b2f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_019e8a0f-41c8-7933-9bd9-d2b82a62156b" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019e8a0f-41c8-718a-86de-5b537f88b2f3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_CostMethodAndOtherLongTermInvestments_019e8a0f-41c8-715a-99f9-6652570685dc" xlink:href="logi-20260630.xsd#logi_CostMethodAndOtherLongTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_019e8a0f-41c8-7933-9bd9-d2b82a62156b" xlink:to="loc_logi_CostMethodAndOtherLongTermInvestments_019e8a0f-41c8-715a-99f9-6652570685dc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_019e8a0f-41c8-7a6b-8337-a9594fee99c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TradingSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_019e8a0f-41c8-7933-9bd9-d2b82a62156b" xlink:to="loc_us-gaap_TradingSecurities_019e8a0f-41c8-7a6b-8337-a9594fee99c9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMiscellaneousNoncurrent_019e8a0f-41c8-7dcd-af28-188b78cf0d1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsMiscellaneousNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_019e8a0f-41c8-7933-9bd9-d2b82a62156b" xlink:to="loc_us-gaap_OtherAssetsMiscellaneousNoncurrent_019e8a0f-41c8-7dcd-af28-188b78cf0d1c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019e8a0f-41c8-735c-97dc-41d54519ef18" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_019e8a0f-41c8-7933-9bd9-d2b82a62156b" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019e8a0f-41c8-735c-97dc-41d54519ef18" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/FairValueMeasurementsScheduleofFinancialAssetsandLiabilitiesClassifiedbyLevelDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#FairValueMeasurementsScheduleofFinancialAssetsandLiabilitiesClassifiedbyLevelDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/FairValueMeasurementsScheduleofFinancialAssetsandLiabilitiesClassifiedbyLevelDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-70a8-a89c-a2b348efc9d1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8a0f-41c8-7589-bb21-dcd222d433c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-70a8-a89c-a2b348efc9d1" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8a0f-41c8-7589-bb21-dcd222d433c0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8a0f-41c8-7a03-a015-bfdd3e8d029a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8a0f-41c8-7589-bb21-dcd222d433c0" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8a0f-41c8-7a03-a015-bfdd3e8d029a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-7a03-a015-bfdd3e8d029a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8a0f-41c8-7a03-a015-bfdd3e8d029a" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-7a03-a015-bfdd3e8d029a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-7f08-9eae-cfef37d7dec2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8a0f-41c8-7a03-a015-bfdd3e8d029a" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-7f08-9eae-cfef37d7dec2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019e8a0f-41c8-7760-b543-60daef0a7f16" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-7f08-9eae-cfef37d7dec2" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019e8a0f-41c8-7760-b543-60daef0a7f16" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019e8a0f-41c8-7f21-8cbb-a12fceb25259" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-7f08-9eae-cfef37d7dec2" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019e8a0f-41c8-7f21-8cbb-a12fceb25259" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019e8a0f-41c8-7441-a18f-65a1ce14f045" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-7f08-9eae-cfef37d7dec2" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019e8a0f-41c8-7441-a18f-65a1ce14f045" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis_019e8a0f-41c8-7aa2-9809-1f610879f09c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8a0f-41c8-7589-bb21-dcd222d433c0" xlink:to="loc_us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis_019e8a0f-41c8-7aa2-9809-1f610879f09c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_019e8a0f-41c8-7aa2-9809-1f610879f09c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis_019e8a0f-41c8-7aa2-9809-1f610879f09c" xlink:to="loc_us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_019e8a0f-41c8-7aa2-9809-1f610879f09c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_019e8a0f-41c8-745d-ba34-368975c081ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis_019e8a0f-41c8-7aa2-9809-1f610879f09c" xlink:to="loc_us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_019e8a0f-41c8-745d-ba34-368975c081ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationExcludingShareBasedPaymentsAndRetirementBenefitsMember_019e8a0f-41c8-75e9-afda-39de6cd211cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredCompensationExcludingShareBasedPaymentsAndRetirementBenefitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_019e8a0f-41c8-745d-ba34-368975c081ef" xlink:to="loc_us-gaap_DeferredCompensationExcludingShareBasedPaymentsAndRetirementBenefitsMember_019e8a0f-41c8-75e9-afda-39de6cd211cc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019e8a0f-41c8-700d-9911-96249e1136a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8a0f-41c8-7589-bb21-dcd222d433c0" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019e8a0f-41c8-700d-9911-96249e1136a6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e8a0f-41c8-700d-9911-96249e1136a6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019e8a0f-41c8-700d-9911-96249e1136a6" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e8a0f-41c8-700d-9911-96249e1136a6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e8a0f-41c8-7583-9d9b-454553840284" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019e8a0f-41c8-700d-9911-96249e1136a6" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e8a0f-41c8-7583-9d9b-454553840284" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashMember_019e8a0f-41c8-7fc5-ba56-4d8796af94e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e8a0f-41c8-7583-9d9b-454553840284" xlink:to="loc_us-gaap_CashMember_019e8a0f-41c8-7fc5-ba56-4d8796af94e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019e8a0f-41c8-78a1-94e7-eed4b760a279" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e8a0f-41c8-7583-9d9b-454553840284" xlink:to="loc_us-gaap_CommonStockMember_019e8a0f-41c8-78a1-94e7-eed4b760a279" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019e8a0f-41c8-7487-a2af-7879acf3d844" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e8a0f-41c8-7583-9d9b-454553840284" xlink:to="loc_us-gaap_MoneyMarketFundsMember_019e8a0f-41c8-7487-a2af-7879acf3d844" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MutualFundMember_019e8a0f-41c8-7b59-b8b6-e47c07c7ab5e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MutualFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e8a0f-41c8-7583-9d9b-454553840284" xlink:to="loc_us-gaap_MutualFundMember_019e8a0f-41c8-7b59-b8b6-e47c07c7ab5e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019f8600-606b-7fac-a885-9010820e50b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8a0f-41c8-7589-bb21-dcd222d433c0" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019f8600-606b-7fac-a885-9010820e50b8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8600-606b-7fac-a885-9010820e50b8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019f8600-606b-7fac-a885-9010820e50b8" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8600-606b-7fac-a885-9010820e50b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8600-606b-75e3-afa9-a4e9db6c2312" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019f8600-606b-7fac-a885-9010820e50b8" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8600-606b-75e3-afa9-a4e9db6c2312" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_019f8600-8100-7847-8b5e-1e6d1d02c7c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8600-606b-75e3-afa9-a4e9db6c2312" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_019f8600-8100-7847-8b5e-1e6d1d02c7c6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_019e8a0f-41c8-7626-9a6b-2c117f0bdd2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-70a8-a89c-a2b348efc9d1" xlink:to="loc_us-gaap_AssetsAbstract_019e8a0f-41c8-7626-9a6b-2c117f0bdd2d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019e8a0f-41c8-77a3-88d7-b59b4592b011" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019e8a0f-41c8-7626-9a6b-2c117f0bdd2d" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019e8a0f-41c8-77a3-88d7-b59b4592b011" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_019e8a0f-41c8-7502-b8c4-34b7645a1e52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TradingSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019e8a0f-41c8-7626-9a6b-2c117f0bdd2d" xlink:to="loc_us-gaap_TradingSecurities_019e8a0f-41c8-7502-b8c4-34b7645a1e52" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_019e8a0f-41c8-78ee-9b7e-819855f2ce6b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019e8a0f-41c8-7626-9a6b-2c117f0bdd2d" xlink:to="loc_us-gaap_DerivativeAssets_019e8a0f-41c8-78ee-9b7e-819855f2ce6b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_019e8a0f-41c8-7f62-a59d-b90813f4ef68" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-70a8-a89c-a2b348efc9d1" xlink:to="loc_us-gaap_LiabilitiesAbstract_019e8a0f-41c8-7f62-a59d-b90813f4ef68" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019e8a0f-41c8-75a8-894f-5bff3a6863a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_019e8a0f-41c8-7f62-a59d-b90813f4ef68" xlink:to="loc_us-gaap_DerivativeLiabilities_019e8a0f-41c8-75a8-894f-5bff3a6863a8" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/FairValueMeasurementsNarrativeDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#FairValueMeasurementsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/FairValueMeasurementsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-7001-bff7-ec8109bbed31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8a0f-41c8-735f-9b83-af93dde5a1e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-7001-bff7-ec8109bbed31" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8a0f-41c8-735f-9b83-af93dde5a1e5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8a0f-41c8-757b-a63c-0ac051373677" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8a0f-41c8-735f-9b83-af93dde5a1e5" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8a0f-41c8-757b-a63c-0ac051373677" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-757b-a63c-0ac051373677_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8a0f-41c8-757b-a63c-0ac051373677" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-757b-a63c-0ac051373677_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-701e-86a6-14a47849e045" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8a0f-41c8-757b-a63c-0ac051373677" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-701e-86a6-14a47849e045" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019e8a0f-41c8-75df-b12b-1e8808732fe6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8a0f-41c8-701e-86a6-14a47849e045" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019e8a0f-41c8-75df-b12b-1e8808732fe6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_019e8a0f-41c8-7907-b97a-42761fde98f4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TradingSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-7001-bff7-ec8109bbed31" xlink:to="loc_us-gaap_TradingSecurities_019e8a0f-41c8-7907-b97a-42761fde98f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_019e8a0f-41c8-77f9-b557-395399def847" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-7001-bff7-ec8109bbed31" xlink:to="loc_us-gaap_EquityMethodInvestments_019e8a0f-41c8-77f9-b557-395399def847" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_019e8a0f-41c8-72df-be59-c13059f44f42" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-7001-bff7-ec8109bbed31" xlink:to="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_019e8a0f-41c8-72df-be59-c13059f44f42" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount_019e8a0f-41c8-7de9-a1ef-be9b50a36820" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-7001-bff7-ec8109bbed31" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount_019e8a0f-41c8-7de9-a1ef-be9b50a36820" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_ImpairmentOfFinancialAssetsMeasuredAtFairValueOnANonrecurringBasis_019e8a0f-41c8-7554-9a68-e3b92e393a63" xlink:href="logi-20260630.xsd#logi_ImpairmentOfFinancialAssetsMeasuredAtFairValueOnANonrecurringBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-7001-bff7-ec8109bbed31" xlink:to="loc_logi_ImpairmentOfFinancialAssetsMeasuredAtFairValueOnANonrecurringBasis_019e8a0f-41c8-7554-9a68-e3b92e393a63" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_NonFinancialAssetImpairmentCharges_019e8a0f-41c8-7395-9c13-841e5d7c6731" xlink:href="logi-20260630.xsd#logi_NonFinancialAssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8a0f-41c8-7001-bff7-ec8109bbed31" xlink:to="loc_logi_NonFinancialAssetImpairmentCharges_019e8a0f-41c8-7395-9c13-841e5d7c6731" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/DerivativeFinancialInstrumentsNarrativeDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#DerivativeFinancialInstrumentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/DerivativeFinancialInstrumentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_019e8a0f-41c8-7773-a8ce-08ccc06aab81" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_019e8a0f-41c8-7afb-b8a8-b905092f6c36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_019e8a0f-41c8-7773-a8ce-08ccc06aab81" xlink:to="loc_us-gaap_DerivativeTable_019e8a0f-41c8-7afb-b8a8-b905092f6c36" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019e8a0f-41c8-7cb5-81a9-cf9798413975" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_019e8a0f-41c8-7afb-b8a8-b905092f6c36" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019e8a0f-41c8-7cb5-81a9-cf9798413975" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019e8a0f-41c8-7cb5-81a9-cf9798413975_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019e8a0f-41c8-7cb5-81a9-cf9798413975" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019e8a0f-41c8-7cb5-81a9-cf9798413975_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019e8a0f-41c8-7751-b463-eb46b92aaeef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019e8a0f-41c8-7cb5-81a9-cf9798413975" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019e8a0f-41c8-7751-b463-eb46b92aaeef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_019e8a0f-41c8-7370-89b4-b07d02e12a63" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019e8a0f-41c8-7751-b463-eb46b92aaeef" xlink:to="loc_us-gaap_ForeignExchangeContractMember_019e8a0f-41c8-7370-89b4-b07d02e12a63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_ForeignExchangeForwardAndSwapMember_019e8a0f-41c8-7a7a-9074-f98e5f99b0bd" xlink:href="logi-20260630.xsd#logi_ForeignExchangeForwardAndSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019e8a0f-41c8-7751-b463-eb46b92aaeef" xlink:to="loc_logi_ForeignExchangeForwardAndSwapMember_019e8a0f-41c8-7a7a-9074-f98e5f99b0bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019e8a0f-41c8-746d-acbe-ce1b6c4d7129" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_019e8a0f-41c8-7afb-b8a8-b905092f6c36" xlink:to="loc_us-gaap_HedgingDesignationAxis_019e8a0f-41c8-746d-acbe-ce1b6c4d7129" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-746d-acbe-ce1b6c4d7129_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019e8a0f-41c8-746d-acbe-ce1b6c4d7129" xlink:to="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-746d-acbe-ce1b6c4d7129_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-710e-bf6b-9d03e7482744" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019e8a0f-41c8-746d-acbe-ce1b6c4d7129" xlink:to="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-710e-bf6b-9d03e7482744" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019e8a0f-41c8-7bb7-80d7-af49fa8c7051" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-710e-bf6b-9d03e7482744" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019e8a0f-41c8-7bb7-80d7-af49fa8c7051" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_019e8a0f-41c8-722b-b4ff-0160a350de88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-710e-bf6b-9d03e7482744" xlink:to="loc_us-gaap_NondesignatedMember_019e8a0f-41c8-722b-b4ff-0160a350de88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019e8a0f-41c8-7db3-88cb-8c53d5babe50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_019e8a0f-41c8-7afb-b8a8-b905092f6c36" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019e8a0f-41c8-7db3-88cb-8c53d5babe50" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-7db3-88cb-8c53d5babe50_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019e8a0f-41c8-7db3-88cb-8c53d5babe50" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-7db3-88cb-8c53d5babe50_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-7038-92ed-6ab40b552561" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019e8a0f-41c8-7db3-88cb-8c53d5babe50" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-7038-92ed-6ab40b552561" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_019e8a0f-41c8-78cd-9cf2-9cb82509113c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-7038-92ed-6ab40b552561" xlink:to="loc_us-gaap_CashFlowHedgingMember_019e8a0f-41c8-78cd-9cf2-9cb82509113c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_ForeignExchangeForwardAndSwapMember_019e8a0f-41c8-7a89-8bb8-852191eb3d3c" xlink:href="logi-20260630.xsd#logi_ForeignExchangeForwardAndSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-7038-92ed-6ab40b552561" xlink:to="loc_logi_ForeignExchangeForwardAndSwapMember_019e8a0f-41c8-7a89-8bb8-852191eb3d3c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_DerivativeInstrumentHedgeCoverageInventoryPurchasePeriod_019f8602-fbea-7f7a-90e3-e2bc2f54622d" xlink:href="logi-20260630.xsd#logi_DerivativeInstrumentHedgeCoverageInventoryPurchasePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019e8a0f-41c8-7773-a8ce-08ccc06aab81" xlink:to="loc_logi_DerivativeInstrumentHedgeCoverageInventoryPurchasePeriod_019f8602-fbea-7f7a-90e3-e2bc2f54622d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_019e8a0f-41c8-7be2-94a6-1cb7e8e22463" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019e8a0f-41c8-7773-a8ce-08ccc06aab81" xlink:to="loc_us-gaap_DerivativeNotionalAmount_019e8a0f-41c8-7be2-94a6-1cb7e8e22463" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths_019e8a0f-41c8-7f2e-b160-ae8e87ad09fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019e8a0f-41c8-7773-a8ce-08ccc06aab81" xlink:to="loc_us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths_019e8a0f-41c8-7f2e-b160-ae8e87ad09fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTermOfContract_019e8a0f-41c8-7f26-a333-36c631e3172c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019e8a0f-41c8-7773-a8ce-08ccc06aab81" xlink:to="loc_us-gaap_DerivativeTermOfContract_019e8a0f-41c8-7f26-a333-36c631e3172c" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/DerivativeFinancialInstrumentsScheduleofGainsandLossesonDerivativeInstrumentsDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#DerivativeFinancialInstrumentsScheduleofGainsandLossesonDerivativeInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/DerivativeFinancialInstrumentsScheduleofGainsandLossesonDerivativeInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019e8a0f-41c8-7b4e-9793-3dea1f5e6377" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019e8a0f-41c8-70c9-828b-155209c3a614" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019e8a0f-41c8-7b4e-9793-3dea1f5e6377" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019e8a0f-41c8-70c9-828b-155209c3a614" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019e8a0f-41c8-7e8c-9de0-dcaf57eb1265" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019e8a0f-41c8-70c9-828b-155209c3a614" xlink:to="loc_us-gaap_HedgingDesignationAxis_019e8a0f-41c8-7e8c-9de0-dcaf57eb1265" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-7e8c-9de0-dcaf57eb1265_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019e8a0f-41c8-7e8c-9de0-dcaf57eb1265" xlink:to="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-7e8c-9de0-dcaf57eb1265_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-7fad-8d1b-de7924a1b793" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019e8a0f-41c8-7e8c-9de0-dcaf57eb1265" xlink:to="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-7fad-8d1b-de7924a1b793" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019e8a0f-41c8-7c8a-9731-f32b0a87c2f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019e8a0f-41c8-7fad-8d1b-de7924a1b793" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019e8a0f-41c8-7c8a-9731-f32b0a87c2f5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019e8a0f-41c8-7406-aee9-04019e5aad1b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_019e8a0f-41c8-70c9-828b-155209c3a614" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019e8a0f-41c8-7406-aee9-04019e5aad1b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-7406-aee9-04019e5aad1b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019e8a0f-41c8-7406-aee9-04019e5aad1b" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-7406-aee9-04019e5aad1b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-74bd-b40b-103fb239265a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019e8a0f-41c8-7406-aee9-04019e5aad1b" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-74bd-b40b-103fb239265a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_019e8a0f-41c8-7a45-932b-c5d5d1c7b7c2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019e8a0f-41c8-74bd-b40b-103fb239265a" xlink:to="loc_us-gaap_CashFlowHedgingMember_019e8a0f-41c8-7a45-932b-c5d5d1c7b7c2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_019e8a0f-41c8-7326-bb63-cb5dd2dd5c21" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019e8a0f-41c8-7b4e-9793-3dea1f5e6377" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_019e8a0f-41c8-7326-bb63-cb5dd2dd5c21" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_019e8a0f-41c8-782d-8a1a-4412b59042e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_019e8a0f-41c8-7b4e-9793-3dea1f5e6377" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_019e8a0f-41c8-782d-8a1a-4412b59042e3" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsSubjecttoAmortizationDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsSubjecttoAmortizationDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsSubjecttoAmortizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8a0f-41c8-7230-a1ac-ab579eab82fb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019e8a0f-41c8-7217-bbf0-31e4d1fff3f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8a0f-41c8-7230-a1ac-ab579eab82fb" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019e8a0f-41c8-7217-bbf0-31e4d1fff3f8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019e8a0f-41c8-7305-b429-dc16dd0b1a3c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019e8a0f-41c8-7217-bbf0-31e4d1fff3f8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019e8a0f-41c8-7305-b429-dc16dd0b1a3c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8a0f-41c8-7305-b429-dc16dd0b1a3c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019e8a0f-41c8-7305-b429-dc16dd0b1a3c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8a0f-41c8-7305-b429-dc16dd0b1a3c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8a0f-41c8-7101-b67a-43e78a9fd772" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019e8a0f-41c8-7305-b429-dc16dd0b1a3c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8a0f-41c8-7101-b67a-43e78a9fd772" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_019e8a0f-41c8-71ed-91e0-9d822f062066" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8a0f-41c8-7101-b67a-43e78a9fd772" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_019e8a0f-41c8-71ed-91e0-9d822f062066" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019e8a0f-41c8-7d1d-8367-da4cfd758170" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8a0f-41c8-7101-b67a-43e78a9fd772" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019e8a0f-41c8-7d1d-8367-da4cfd758170" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019e8a0f-41c8-7572-a8a7-ea6334ac71dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8a0f-41c8-7101-b67a-43e78a9fd772" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019e8a0f-41c8-7572-a8a7-ea6334ac71dd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_019e8a0f-41c8-7beb-b78b-a2c9dc8353bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8a0f-41c8-7230-a1ac-ab579eab82fb" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_019e8a0f-41c8-7beb-b78b-a2c9dc8353bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019e8a0f-41c8-7b4c-890d-4644ea6544b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8a0f-41c8-7230-a1ac-ab579eab82fb" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019e8a0f-41c8-7b4c-890d-4644ea6544b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019e8a0f-41c8-715f-bf64-a60f218c29c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8a0f-41c8-7230-a1ac-ab579eab82fb" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019e8a0f-41c8-715f-bf64-a60f218c29c0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_IntangibleAssetsForeignCurrencyTranslationGainLossGrossExcludingGoodwill_019e8a0f-41c8-73e2-9095-8f29946b8434" xlink:href="logi-20260630.xsd#logi_IntangibleAssetsForeignCurrencyTranslationGainLossGrossExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8a0f-41c8-7230-a1ac-ab579eab82fb" xlink:to="loc_logi_IntangibleAssetsForeignCurrencyTranslationGainLossGrossExcludingGoodwill_019e8a0f-41c8-73e2-9095-8f29946b8434" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_IntangibleAssetsForeignCurrencyTranslationGainLossAccumulatedAmortization_019e8a0f-41c8-7c9c-bc62-7701b874748d" xlink:href="logi-20260630.xsd#logi_IntangibleAssetsForeignCurrencyTranslationGainLossAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8a0f-41c8-7230-a1ac-ab579eab82fb" xlink:to="loc_logi_IntangibleAssetsForeignCurrencyTranslationGainLossAccumulatedAmortization_019e8a0f-41c8-7c9c-bc62-7701b874748d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_IntangibleAssetsForeignCurrencyTranslationGainLossNetExcludingGoodwill_019e8a0f-41c8-731e-9859-ce9fbd60ed2d" xlink:href="logi-20260630.xsd#logi_IntangibleAssetsForeignCurrencyTranslationGainLossNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8a0f-41c8-7230-a1ac-ab579eab82fb" xlink:to="loc_logi_IntangibleAssetsForeignCurrencyTranslationGainLossNetExcludingGoodwill_019e8a0f-41c8-731e-9859-ce9fbd60ed2d" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/FinancingArrangementsDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#FinancingArrangementsDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/FinancingArrangementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_019e8a0f-41c9-7b2e-a62f-5ad58be2dd8b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_019e8a0f-41c9-7127-887c-476d3db05a11" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019e8a0f-41c9-7b2e-a62f-5ad58be2dd8b" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_019e8a0f-41c9-7127-887c-476d3db05a11" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019e8a0f-41c9-7f3d-b9c4-224f61003553" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019e8a0f-41c9-7127-887c-476d3db05a11" xlink:to="loc_us-gaap_CreditFacilityAxis_019e8a0f-41c9-7f3d-b9c4-224f61003553" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019e8a0f-41c9-7f3d-b9c4-224f61003553_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019e8a0f-41c9-7f3d-b9c4-224f61003553" xlink:to="loc_us-gaap_CreditFacilityDomain_019e8a0f-41c9-7f3d-b9c4-224f61003553_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019e8a0f-41c9-7a8b-9683-311636f81ee4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019e8a0f-41c9-7f3d-b9c4-224f61003553" xlink:to="loc_us-gaap_CreditFacilityDomain_019e8a0f-41c9-7a8b-9683-311636f81ee4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019e8a0f-41c9-7922-9bfb-035d13bed16e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019e8a0f-41c9-7a8b-9683-311636f81ee4" xlink:to="loc_us-gaap_LineOfCreditMember_019e8a0f-41c9-7922-9bfb-035d13bed16e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019e8a0f-41c9-7e1f-8b13-b1d4948f126f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019e8a0f-41c9-7a8b-9683-311636f81ee4" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019e8a0f-41c9-7e1f-8b13-b1d4948f126f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_019e8a0f-41c9-7a26-9303-d3ef470c3393" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LetterOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019e8a0f-41c9-7a8b-9683-311636f81ee4" xlink:to="loc_us-gaap_LetterOfCreditMember_019e8a0f-41c9-7a26-9303-d3ef470c3393" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019e8a0f-41c9-7bed-96cd-55e164eda3d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019e8a0f-41c9-7127-887c-476d3db05a11" xlink:to="loc_us-gaap_DebtInstrumentAxis_019e8a0f-41c9-7bed-96cd-55e164eda3d0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019e8a0f-41c9-7bed-96cd-55e164eda3d0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019e8a0f-41c9-7bed-96cd-55e164eda3d0" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019e8a0f-41c9-7bed-96cd-55e164eda3d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019e8a0f-41c9-7ee9-b841-3ee28911707d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019e8a0f-41c9-7bed-96cd-55e164eda3d0" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019e8a0f-41c9-7ee9-b841-3ee28911707d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_SeniorUnsecuredRevolvingCreditFacilityMember_019e8a0f-41c9-7066-b898-ece9798a4803" xlink:href="logi-20260630.xsd#logi_SeniorUnsecuredRevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019e8a0f-41c9-7ee9-b841-3ee28911707d" xlink:to="loc_logi_SeniorUnsecuredRevolvingCreditFacilityMember_019e8a0f-41c9-7066-b898-ece9798a4803" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019e8a0f-41c9-7707-ac8b-2c409b47fa46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019e8a0f-41c9-7127-887c-476d3db05a11" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019e8a0f-41c9-7707-ac8b-2c409b47fa46" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019e8a0f-41c9-7707-ac8b-2c409b47fa46_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019e8a0f-41c9-7707-ac8b-2c409b47fa46" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019e8a0f-41c9-7707-ac8b-2c409b47fa46_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019e8a0f-41c9-7973-88cf-8231820be15a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019e8a0f-41c9-7707-ac8b-2c409b47fa46" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019e8a0f-41c9-7973-88cf-8231820be15a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019e8a0f-41c9-7b2e-8955-dea2beae0c92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019e8a0f-41c9-7973-88cf-8231820be15a" xlink:to="loc_us-gaap_LineOfCreditMember_019e8a0f-41c9-7b2e-8955-dea2beae0c92" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019e8a0f-41c9-731c-9535-f8b892b74140" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019e8a0f-41c9-7127-887c-476d3db05a11" xlink:to="loc_srt_RangeAxis_019e8a0f-41c9-731c-9535-f8b892b74140" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e8a0f-41c9-731c-9535-f8b892b74140_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019e8a0f-41c9-731c-9535-f8b892b74140" xlink:to="loc_srt_RangeMember_019e8a0f-41c9-731c-9535-f8b892b74140_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e8a0f-41c9-7779-84bd-e4572d46b68d" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019e8a0f-41c9-731c-9535-f8b892b74140" xlink:to="loc_srt_RangeMember_019e8a0f-41c9-7779-84bd-e4572d46b68d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019e8a0f-41c9-791f-bbeb-f4b634bd7152" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e8a0f-41c9-7779-84bd-e4572d46b68d" xlink:to="loc_srt_MinimumMember_019e8a0f-41c9-791f-bbeb-f4b634bd7152" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019e8a0f-41c9-7620-b457-85a602c69bf9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e8a0f-41c9-7779-84bd-e4572d46b68d" xlink:to="loc_srt_MaximumMember_019e8a0f-41c9-7620-b457-85a602c69bf9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019e8a0f-41c9-70ea-b8e5-619d4224adde" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019e8a0f-41c9-7b2e-a62f-5ad58be2dd8b" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019e8a0f-41c9-70ea-b8e5-619d4224adde" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_LineOfCreditAdditionalCommitmentIncreaseLimit_019e8a0f-41c9-7fbf-8d79-98df0fbad437" xlink:href="logi-20260630.xsd#logi_LineOfCreditAdditionalCommitmentIncreaseLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019e8a0f-41c9-7b2e-a62f-5ad58be2dd8b" xlink:to="loc_logi_LineOfCreditAdditionalCommitmentIncreaseLimit_019e8a0f-41c9-7fbf-8d79-98df0fbad437" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_DebtInstrumentExtensionTermPeriod_019e8a0f-41c9-7949-8b40-8e06a886f84a" xlink:href="logi-20260630.xsd#logi_DebtInstrumentExtensionTermPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019e8a0f-41c9-7b2e-a62f-5ad58be2dd8b" xlink:to="loc_logi_DebtInstrumentExtensionTermPeriod_019e8a0f-41c9-7949-8b40-8e06a886f84a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_DebtInstrumentNumberOfTermExtensions_019e8a0f-41c9-78b1-8941-418c454cdd74" xlink:href="logi-20260630.xsd#logi_DebtInstrumentNumberOfTermExtensions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019e8a0f-41c9-7b2e-a62f-5ad58be2dd8b" xlink:to="loc_logi_DebtInstrumentNumberOfTermExtensions_019e8a0f-41c9-78b1-8941-418c454cdd74" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019e8a0f-41c9-72ad-835d-6805e56f2f27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019e8a0f-41c9-7b2e-a62f-5ad58be2dd8b" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019e8a0f-41c9-72ad-835d-6805e56f2f27" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_019e8a0f-41c9-7e6d-8b7c-baf01830d262" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019e8a0f-41c9-7b2e-a62f-5ad58be2dd8b" xlink:to="loc_us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_019e8a0f-41c9-7e6d-8b7c-baf01830d262" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_019e8a0f-41c9-7c29-9de7-439c45e4bdd4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019e8a0f-41c9-7b2e-a62f-5ad58be2dd8b" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_019e8a0f-41c9-7c29-9de7-439c45e4bdd4" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/CommitmentsandContingenciesNarrativeDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#CommitmentsandContingenciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/CommitmentsandContingenciesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems_019e8a0f-41c9-752e-b8eb-d1d33393a9f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsTable_019e8a0f-41c9-7976-a931-40ba04f79194" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019e8a0f-41c9-752e-b8eb-d1d33393a9f7" xlink:to="loc_us-gaap_OtherCommitmentsTable_019e8a0f-41c9-7976-a931-40ba04f79194" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_019e8a0f-41c9-7843-bf5a-7b3a82922986" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsByNatureAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_019e8a0f-41c9-7976-a931-40ba04f79194" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_019e8a0f-41c9-7843-bf5a-7b3a82922986" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_019e8a0f-41c9-7843-bf5a-7b3a82922986_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_019e8a0f-41c9-7843-bf5a-7b3a82922986" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_019e8a0f-41c9-7843-bf5a-7b3a82922986_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_019e8a0f-41c9-7939-871a-0c7b13243e89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_019e8a0f-41c9-7843-bf5a-7b3a82922986" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_019e8a0f-41c9-7939-871a-0c7b13243e89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndemnificationGuaranteeMember_019e8a0f-41c9-7b7c-87bd-3825caf23542" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IndemnificationGuaranteeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_019e8a0f-41c9-7939-871a-0c7b13243e89" xlink:to="loc_us-gaap_IndemnificationGuaranteeMember_019e8a0f-41c9-7b7c-87bd-3825caf23542" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019e8a0f-41c9-7f45-bd8a-937a7d219ec7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019e8a0f-41c9-752e-b8eb-d1d33393a9f7" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019e8a0f-41c9-7f45-bd8a-937a7d219ec7" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/ShareholdersEquityNarrativeDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#ShareholdersEquityNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/ShareholdersEquityNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019e8a0f-41c9-7650-a105-ce0bfb9e9139" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019e8a0f-41c9-7650-a105-ce0bfb9e9139" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019e8a0f-41c9-723a-8851-baff14b01d15" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019e8a0f-41c9-7650-a105-ce0bfb9e9139" xlink:to="loc_srt_RangeAxis_019e8a0f-41c9-723a-8851-baff14b01d15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e8a0f-41c9-723a-8851-baff14b01d15_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019e8a0f-41c9-723a-8851-baff14b01d15" xlink:to="loc_srt_RangeMember_019e8a0f-41c9-723a-8851-baff14b01d15_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e8a0f-41c9-7513-bc71-fffe039ca3d2" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019e8a0f-41c9-723a-8851-baff14b01d15" xlink:to="loc_srt_RangeMember_019e8a0f-41c9-7513-bc71-fffe039ca3d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019e8a0f-41c9-772e-960d-fde5692410e7" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e8a0f-41c9-7513-bc71-fffe039ca3d2" xlink:to="loc_srt_MinimumMember_019e8a0f-41c9-772e-960d-fde5692410e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019e8a0f-41c9-7f65-8ec2-d5ae44db6d20" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e8a0f-41c9-7513-bc71-fffe039ca3d2" xlink:to="loc_srt_MaximumMember_019e8a0f-41c9-7f65-8ec2-d5ae44db6d20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-41c9-7359-a6ce-6d35e168f786" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019e8a0f-41c9-7650-a105-ce0bfb9e9139" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-41c9-7359-a6ce-6d35e168f786" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-7359-a6ce-6d35e168f786_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-41c9-7359-a6ce-6d35e168f786" xlink:to="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-7359-a6ce-6d35e168f786_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-779b-85bf-e4f7d9e05b88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-41c9-7359-a6ce-6d35e168f786" xlink:to="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-779b-85bf-e4f7d9e05b88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_CommonStockCapitalSharesReservedForFutureIssuanceEmployeeEquityIncentivePlansMember_019e8a0f-41c9-7d45-80eb-ceb2d8df0aa6" xlink:href="logi-20260630.xsd#logi_CommonStockCapitalSharesReservedForFutureIssuanceEmployeeEquityIncentivePlansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-779b-85bf-e4f7d9e05b88" xlink:to="loc_logi_CommonStockCapitalSharesReservedForFutureIssuanceEmployeeEquityIncentivePlansMember_019e8a0f-41c9-7d45-80eb-ceb2d8df0aa6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_CommonStockCapitalSharesReservedForFutureIssuanceConversionRightsUnderFutureConvertibleBondIssuanceMember_019e8a0f-41c9-7abc-8ac4-a2c1dffeb296" xlink:href="logi-20260630.xsd#logi_CommonStockCapitalSharesReservedForFutureIssuanceConversionRightsUnderFutureConvertibleBondIssuanceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-779b-85bf-e4f7d9e05b88" xlink:to="loc_logi_CommonStockCapitalSharesReservedForFutureIssuanceConversionRightsUnderFutureConvertibleBondIssuanceMember_019e8a0f-41c9-7abc-8ac4-a2c1dffeb296" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_019e8a0f-41c9-7398-9449-d46fb0bd6738" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019e8a0f-41c9-7650-a105-ce0bfb9e9139" xlink:to="loc_srt_ShareRepurchaseProgramAxis_019e8a0f-41c9-7398-9449-d46fb0bd6738" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7398-9449-d46fb0bd6738_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019e8a0f-41c9-7398-9449-d46fb0bd6738" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7398-9449-d46fb0bd6738_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7bd4-84cc-e0da3cecf181" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019e8a0f-41c9-7398-9449-d46fb0bd6738" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7bd4-84cc-e0da3cecf181" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_TwentyTwentyThreeShareRepurchaseProgramMember_019e8a0f-41c9-79b2-a3d8-7ee465ef678a" xlink:href="logi-20260630.xsd#logi_TwentyTwentyThreeShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7bd4-84cc-e0da3cecf181" xlink:to="loc_logi_TwentyTwentyThreeShareRepurchaseProgramMember_019e8a0f-41c9-79b2-a3d8-7ee465ef678a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_TwentyTwentySixShareRepurchaseProgramMember_019eba34-2bbc-755f-b8c8-135347e0bf8d" xlink:href="logi-20260630.xsd#logi_TwentyTwentySixShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7bd4-84cc-e0da3cecf181" xlink:to="loc_logi_TwentyTwentySixShareRepurchaseProgramMember_019eba34-2bbc-755f-b8c8-135347e0bf8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValueOutstanding_019e8a0f-41c9-76c8-a942-0fe93002e9f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValueOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_us-gaap_CommonStockValueOutstanding_019e8a0f-41c9-76c8-a942-0fe93002e9f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019e8a0f-41c9-75cf-b803-b383714f7d6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_us-gaap_CommonStockSharesIssued_019e8a0f-41c9-75cf-b803-b383714f7d6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_019e8a0f-41c9-7842-9823-b43bd6685d9c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_019e8a0f-41c9-7842-9823-b43bd6685d9c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019e8a0f-41c9-72ea-8ddd-50bb29892491" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_us-gaap_TreasuryStockCommonShares_019e8a0f-41c9-72ea-8ddd-50bb29892491" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_CapitalBandProvisionAdjustmentToCapitalShares_019e8a0f-41c9-7201-96ed-f998751b0fc1" xlink:href="logi-20260630.xsd#logi_CapitalBandProvisionAdjustmentToCapitalShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_logi_CapitalBandProvisionAdjustmentToCapitalShares_019e8a0f-41c9-7201-96ed-f998751b0fc1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_CapitalBandProvisionAdjustmentToCapitalSharesPeriod_019e8a0f-41c9-7926-8e90-d1845cca5c8c" xlink:href="logi-20260630.xsd#logi_CapitalBandProvisionAdjustmentToCapitalSharesPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_logi_CapitalBandProvisionAdjustmentToCapitalSharesPeriod_019e8a0f-41c9-7926-8e90-d1845cca5c8c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_NumberOfSharesIssuableOutOfConditionalCapital_019e8a0f-41c9-7569-af38-a3f9d402d3cd" xlink:href="logi-20260630.xsd#logi_NumberOfSharesIssuableOutOfConditionalCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_logi_NumberOfSharesIssuableOutOfConditionalCapital_019e8a0f-41c9-7569-af38-a3f9d402d3cd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramPeriodInForce1_019e8a0f-41c9-7dc0-bdee-1930c3ac2658" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchaseProgramPeriodInForce1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_us-gaap_StockRepurchaseProgramPeriodInForce1_019e8a0f-41c9-7dc0-bdee-1930c3ac2658" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019e8a0f-41c9-71d9-aa0d-0f1f16caca28" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019e8a0f-41c9-71d9-aa0d-0f1f16caca28" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_ShareRepurchaseProgramIncreaseInAuthorizedAmount_019e8a0f-41c9-7115-98e6-39bac1963ee0" xlink:href="logi-20260630.xsd#logi_ShareRepurchaseProgramIncreaseInAuthorizedAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_logi_ShareRepurchaseProgramIncreaseInAuthorizedAmount_019e8a0f-41c9-7115-98e6-39bac1963ee0" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_019eba5d-9a68-75ee-a513-b324838dc9d9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_019eba5d-9a68-75ee-a513-b324838dc9d9" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019e8a0f-41c9-709c-a764-65cf4279f9fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019e8a0f-41c9-709c-a764-65cf4279f9fa" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_StockRepurchaseProgramThresholdMaximumSharesHeldPercentage_019e8a0f-41c9-76e6-a638-17aa22b90b8e" xlink:href="logi-20260630.xsd#logi_StockRepurchaseProgramThresholdMaximumSharesHeldPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_logi_StockRepurchaseProgramThresholdMaximumSharesHeldPercentage_019e8a0f-41c9-76e6-a638-17aa22b90b8e" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_StockRepurchaseProgramThresholdMaximumSharesAvailableForPurchase_019e8a0f-41c9-7002-a6e0-d84c0f56773e" xlink:href="logi-20260630.xsd#logi_StockRepurchaseProgramThresholdMaximumSharesAvailableForPurchase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_logi_StockRepurchaseProgramThresholdMaximumSharesAvailableForPurchase_019e8a0f-41c9-7002-a6e0-d84c0f56773e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_TreasuryStockSharesAcquiredForCancellation_019e8a0f-41c9-74f9-be2d-f1502dd58440" xlink:href="logi-20260630.xsd#logi_TreasuryStockSharesAcquiredForCancellation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_logi_TreasuryStockSharesAcquiredForCancellation_019e8a0f-41c9-74f9-be2d-f1502dd58440" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_TreasuryStockSharesAcquiredForEquityIncentivePlansOrPotentialAcquisitions_019e8a0f-41c9-7402-841b-d9c819a50999" xlink:href="logi-20260630.xsd#logi_TreasuryStockSharesAcquiredForEquityIncentivePlansOrPotentialAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e8a0f-41c9-7551-ac00-00c64ccfce7a" xlink:to="loc_logi_TreasuryStockSharesAcquiredForEquityIncentivePlansOrPotentialAcquisitions_019e8a0f-41c9-7402-841b-d9c819a50999" xlink:type="arc" order="15"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/ShareholdersEquityScheduleofSharesRepurchasedDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#ShareholdersEquityScheduleofSharesRepurchasedDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/ShareholdersEquityScheduleofSharesRepurchasedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019e8a0f-41c9-75ed-a1f8-53bd09381659" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityClassOfTreasuryStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfTreasuryStockTable_019e8a0f-41c9-7e7f-a2ed-33ebc84864fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfTreasuryStockTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019e8a0f-41c9-75ed-a1f8-53bd09381659" xlink:to="loc_us-gaap_ClassOfTreasuryStockTable_019e8a0f-41c9-7e7f-a2ed-33ebc84864fa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_019e8a0f-41c9-7285-8f14-fcc99f236285" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ClassOfTreasuryStockTable_019e8a0f-41c9-7e7f-a2ed-33ebc84864fa" xlink:to="loc_srt_ShareRepurchaseProgramAxis_019e8a0f-41c9-7285-8f14-fcc99f236285" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7285-8f14-fcc99f236285_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019e8a0f-41c9-7285-8f14-fcc99f236285" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7285-8f14-fcc99f236285_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7acc-b523-fe6a7d507b45" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019e8a0f-41c9-7285-8f14-fcc99f236285" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7acc-b523-fe6a7d507b45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_TwentyTwentyThreeShareRepurchaseProgramMember_019e8a0f-41c9-7ef6-bd29-e4640b206587" xlink:href="logi-20260630.xsd#logi_TwentyTwentyThreeShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7acc-b523-fe6a7d507b45" xlink:to="loc_logi_TwentyTwentyThreeShareRepurchaseProgramMember_019e8a0f-41c9-7ef6-bd29-e4640b206587" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_TwentyTwentySixShareRepurchaseProgramMember_019eba56-3ba8-7985-a738-cff7339fbc02" xlink:href="logi-20260630.xsd#logi_TwentyTwentySixShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019e8a0f-41c9-7acc-b523-fe6a7d507b45" xlink:to="loc_logi_TwentyTwentySixShareRepurchaseProgramMember_019eba56-3ba8-7985-a738-cff7339fbc02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_019e8a0f-41c9-79c9-b1bf-22adfdb23af3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019e8a0f-41c9-75ed-a1f8-53bd09381659" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_019e8a0f-41c9-79c9-b1bf-22adfdb23af3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_019e8a0f-41c9-7783-bf04-a6f1a17ad1dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019e8a0f-41c9-75ed-a1f8-53bd09381659" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_019e8a0f-41c9-7783-bf04-a6f1a17ad1dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_StockRepurchasedDuringPeriodNotYetPaidValue_019e8a0f-41c9-7f26-b3fc-ff79f99388b1" xlink:href="logi-20260630.xsd#logi_StockRepurchasedDuringPeriodNotYetPaidValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019e8a0f-41c9-75ed-a1f8-53bd09381659" xlink:to="loc_logi_StockRepurchasedDuringPeriodNotYetPaidValue_019e8a0f-41c9-7f26-b3fc-ff79f99388b1" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/ShareholdersEquityScheduleofComponentsofAccumulatedOtherComprehensiveLossDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#ShareholdersEquityScheduleofComponentsofAccumulatedOtherComprehensiveLossDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/ShareholdersEquityScheduleofComponentsofAccumulatedOtherComprehensiveLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019e8a0f-41c9-73cd-a9ad-cd60aa56a22f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019e8a0f-41c9-72a0-9e3b-e4eef08c5172" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019e8a0f-41c9-73cd-a9ad-cd60aa56a22f" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019e8a0f-41c9-72a0-9e3b-e4eef08c5172" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-41c9-7cf7-90ab-976f9626836a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019e8a0f-41c9-72a0-9e3b-e4eef08c5172" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-41c9-7cf7-90ab-976f9626836a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-7cf7-90ab-976f9626836a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-41c9-7cf7-90ab-976f9626836a" xlink:to="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-7cf7-90ab-976f9626836a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-7515-a96d-0ed310a8456f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e8a0f-41c9-7cf7-90ab-976f9626836a" xlink:to="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-7515-a96d-0ed310a8456f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e8a0f-41c9-7b50-af3a-56321f5781a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8a0f-41c9-7515-a96d-0ed310a8456f" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e8a0f-41c9-7b50-af3a-56321f5781a0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019e8a0f-41c9-7c2b-a5ab-c4b824e87cce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e8a0f-41c9-7b50-af3a-56321f5781a0" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019e8a0f-41c9-7c2b-a5ab-c4b824e87cce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019e8a0f-41c9-74a4-86ae-a82d102253a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e8a0f-41c9-7b50-af3a-56321f5781a0" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019e8a0f-41c9-74a4-86ae-a82d102253a7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019e8a0f-41c9-7909-aac8-b09bd8d43f6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e8a0f-41c9-7b50-af3a-56321f5781a0" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019e8a0f-41c9-7909-aac8-b09bd8d43f6c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019e8a0f-41c9-753b-8a42-de66bd334d0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019e8a0f-41c9-73cd-a9ad-cd60aa56a22f" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019e8a0f-41c9-753b-8a42-de66bd334d0c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e8a0f-41c9-7ab2-8407-b60c34c6ee35" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019e8a0f-41c9-753b-8a42-de66bd334d0c" xlink:to="loc_us-gaap_StockholdersEquity_019e8a0f-41c9-7ab2-8407-b60c34c6ee35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019e8a0f-41c9-798c-a44d-5d02ae8ae3ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019e8a0f-41c9-753b-8a42-de66bd334d0c" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019e8a0f-41c9-798c-a44d-5d02ae8ae3ec" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e8a0f-41c9-7d3c-b17c-05ef47e263c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/SegmentInformationScheduleofSegmentRevenueGrossProfitandNetIncomeDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#SegmentInformationScheduleofSegmentRevenueGrossProfitandNetIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/SegmentInformationScheduleofSegmentRevenueGrossProfitandNetIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-77f1-9689-e3c220e9149d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-786a-8122-bf0a822c41c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-77f1-9689-e3c220e9149d" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-786a-8122-bf0a822c41c0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019e8a0f-41c9-7b52-8883-af1e6d233e9e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-786a-8122-bf0a822c41c0" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019e8a0f-41c9-7b52-8883-af1e6d233e9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019e8a0f-41c9-7b52-8883-af1e6d233e9e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019e8a0f-41c9-7b52-8883-af1e6d233e9e" xlink:to="loc_us-gaap_SegmentDomain_019e8a0f-41c9-7b52-8883-af1e6d233e9e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019e8a0f-41c9-7524-a2f6-6b37f42a3e1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019e8a0f-41c9-7b52-8883-af1e6d233e9e" xlink:to="loc_us-gaap_SegmentDomain_019e8a0f-41c9-7524-a2f6-6b37f42a3e1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_ReportableSegmentMember_019e8a0f-41c9-7c2d-b668-38ae9774b504" xlink:href="logi-20260630.xsd#logi_ReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019e8a0f-41c9-7524-a2f6-6b37f42a3e1c" xlink:to="loc_logi_ReportableSegmentMember_019e8a0f-41c9-7c2d-b668-38ae9774b504" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e8a0f-41c9-7166-a5ea-f4e9ba64f516" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-77f1-9689-e3c220e9149d" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e8a0f-41c9-7166-a5ea-f4e9ba64f516" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-77f1-9689-e3c220e9149d" xlink:to="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_CostOfGoodsSoldExcludingAmortizationOfIntangibleAssets_019e8a0f-41c9-7692-9d34-aaadd4f71eaf" xlink:href="logi-20260630.xsd#logi_CostOfGoodsSoldExcludingAmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:to="loc_logi_CostOfGoodsSoldExcludingAmortizationOfIntangibleAssets_019e8a0f-41c9-7692-9d34-aaadd4f71eaf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_SellingAndMarketingExpenseExcludingShareBasedCompensation_019edde6-58a5-7cbb-85fd-0780300f7e01" xlink:href="logi-20260630.xsd#logi_SellingAndMarketingExpenseExcludingShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:to="loc_logi_SellingAndMarketingExpenseExcludingShareBasedCompensation_019edde6-58a5-7cbb-85fd-0780300f7e01" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_ResearchAndDevelopmentExpenseExcludingShareBasedCompensation_019edde6-58a5-7081-b818-f89a4fc6f0b0" xlink:href="logi-20260630.xsd#logi_ResearchAndDevelopmentExpenseExcludingShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:to="loc_logi_ResearchAndDevelopmentExpenseExcludingShareBasedCompensation_019edde6-58a5-7081-b818-f89a4fc6f0b0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_GeneralAndAdministrativeExpenseExcludingShareBasedCompensation_019edde6-58a5-723c-803b-f33da5838ab3" xlink:href="logi-20260630.xsd#logi_GeneralAndAdministrativeExpenseExcludingShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:to="loc_logi_GeneralAndAdministrativeExpenseExcludingShareBasedCompensation_019edde6-58a5-723c-803b-f33da5838ab3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e8a0f-41c9-7957-b5ff-6242c7b7324f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e8a0f-41c9-7957-b5ff-6242c7b7324f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_AmortizationOfIntangibleAssetsAndAmortizationOfAcquisitionRelatedCosts_019e8a0f-41c9-7be1-ab6b-fdda286a7616" xlink:href="logi-20260630.xsd#logi_AmortizationOfIntangibleAssetsAndAmortizationOfAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:to="loc_logi_AmortizationOfIntangibleAssetsAndAmortizationOfAcquisitionRelatedCosts_019e8a0f-41c9-7be1-ab6b-fdda286a7616" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_019e8a0f-41c9-79ff-913b-ba560f2991e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_019e8a0f-41c9-79ff-913b-ba560f2991e5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_019e8a0f-41c9-7f87-8ca6-a2e9cfe176a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_019e8a0f-41c9-7f87-8ca6-a2e9cfe176a3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019e8a0f-41c9-7531-a927-b4946796b302" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019e8a0f-41c9-79dd-a991-46c8efc38f50" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019e8a0f-41c9-7531-a927-b4946796b302" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e8a0f-41c9-75f9-872e-d52195aa85b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-77f1-9689-e3c220e9149d" xlink:to="loc_us-gaap_NetIncomeLoss_019e8a0f-41c9-75f9-872e-d52195aa85b2" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/SegmentInformationScheduleofNetSalesbyProductCategoriesExcludingIntercompanyTransactionsDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#SegmentInformationScheduleofNetSalesbyProductCategoriesExcludingIntercompanyTransactionsDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/SegmentInformationScheduleofNetSalesbyProductCategoriesExcludingIntercompanyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-7e10-ad38-cfbabd1b5fbc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-7917-935c-cadf86770d3e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-7e10-ad38-cfbabd1b5fbc" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-7917-935c-cadf86770d3e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019e8a0f-41c9-7dc7-86d9-0f7427164cc3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-7917-935c-cadf86770d3e" xlink:to="loc_srt_ProductOrServiceAxis_019e8a0f-41c9-7dc7-86d9-0f7427164cc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-7dc7-86d9-0f7427164cc3_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019e8a0f-41c9-7dc7-86d9-0f7427164cc3" xlink:to="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-7dc7-86d9-0f7427164cc3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-793a-9163-da53f09158cd" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019e8a0f-41c9-7dc7-86d9-0f7427164cc3" xlink:to="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-793a-9163-da53f09158cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_RetailGamingMember_019e8a0f-41c9-75a3-b4ed-0a343c6e3740" xlink:href="logi-20260630.xsd#logi_RetailGamingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-793a-9163-da53f09158cd" xlink:to="loc_logi_RetailGamingMember_019e8a0f-41c9-75a3-b4ed-0a343c6e3740" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_RetailKeyboardsDesktopsMember_019e8a0f-41c9-7e1d-9f4d-4fcc29d4debd" xlink:href="logi-20260630.xsd#logi_RetailKeyboardsDesktopsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-793a-9163-da53f09158cd" xlink:to="loc_logi_RetailKeyboardsDesktopsMember_019e8a0f-41c9-7e1d-9f4d-4fcc29d4debd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_RetailPointingDevicesMember_019e8a0f-41c9-703c-93e9-e54c782b7fb8" xlink:href="logi-20260630.xsd#logi_RetailPointingDevicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-793a-9163-da53f09158cd" xlink:to="loc_logi_RetailPointingDevicesMember_019e8a0f-41c9-703c-93e9-e54c782b7fb8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_RetailVideoCollaborationMember_019e8a0f-41c9-7b22-95ba-03617a30e705" xlink:href="logi-20260630.xsd#logi_RetailVideoCollaborationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-793a-9163-da53f09158cd" xlink:to="loc_logi_RetailVideoCollaborationMember_019e8a0f-41c9-7b22-95ba-03617a30e705" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_RetailWebcamsMember_019e8a0f-41c9-70af-bf5b-e42cc281190d" xlink:href="logi-20260630.xsd#logi_RetailWebcamsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-793a-9163-da53f09158cd" xlink:to="loc_logi_RetailWebcamsMember_019e8a0f-41c9-70af-bf5b-e42cc281190d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_RetailTabletAndOtherAccessoriesMember_019e8a0f-41c9-7a54-af9c-151f7a7a8d0b" xlink:href="logi-20260630.xsd#logi_RetailTabletAndOtherAccessoriesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-793a-9163-da53f09158cd" xlink:to="loc_logi_RetailTabletAndOtherAccessoriesMember_019e8a0f-41c9-7a54-af9c-151f7a7a8d0b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_RetailHeadsetsMember_019e8a0f-41c9-7475-adba-e521ffdf782f" xlink:href="logi-20260630.xsd#logi_RetailHeadsetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-793a-9163-da53f09158cd" xlink:to="loc_logi_RetailHeadsetsMember_019e8a0f-41c9-7475-adba-e521ffdf782f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_OtherRetailProductsMember_019e8a0f-41c9-7360-a287-07de7e4fefba" xlink:href="logi-20260630.xsd#logi_OtherRetailProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8a0f-41c9-793a-9163-da53f09158cd" xlink:to="loc_logi_OtherRetailProductsMember_019e8a0f-41c9-7360-a287-07de7e4fefba" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e8a0f-41c9-7e3c-b3cd-2e7421bfd512" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-7e10-ad38-cfbabd1b5fbc" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e8a0f-41c9-7e3c-b3cd-2e7421bfd512" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/SegmentInformationScheduleofNetSalesandLongLivedAssetsbyGeographicRegionDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#SegmentInformationScheduleofNetSalesandLongLivedAssetsbyGeographicRegionDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/SegmentInformationScheduleofNetSalesandLongLivedAssetsbyGeographicRegionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019e8a0f-41c9-7da8-90ed-1e94284d4aaf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019e8a0f-41c9-7c1d-ab14-2f195dab4047" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019e8a0f-41c9-7da8-90ed-1e94284d4aaf" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019e8a0f-41c9-7c1d-ab14-2f195dab4047" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019e8a0f-41c9-7251-afb4-bfe15a65fd53" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019e8a0f-41c9-7c1d-ab14-2f195dab4047" xlink:to="loc_srt_StatementGeographicalAxis_019e8a0f-41c9-7251-afb4-bfe15a65fd53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7251-afb4-bfe15a65fd53_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019e8a0f-41c9-7251-afb4-bfe15a65fd53" xlink:to="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7251-afb4-bfe15a65fd53_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7747-b381-5df518d2bed1" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019e8a0f-41c9-7251-afb4-bfe15a65fd53" xlink:to="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7747-b381-5df518d2bed1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_019e8a0f-41c9-73dc-b3cb-a397bf737de0" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7747-b381-5df518d2bed1" xlink:to="loc_srt_AmericasMember_019e8a0f-41c9-73dc-b3cb-a397bf737de0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_019e8a0f-41c9-7ef7-afed-4f698e02c431" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7747-b381-5df518d2bed1" xlink:to="loc_us-gaap_EMEAMember_019e8a0f-41c9-7ef7-afed-4f698e02c431" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_019e8a0f-41c9-7c27-93c5-e237c6ad7267" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7747-b381-5df518d2bed1" xlink:to="loc_srt_AsiaPacificMember_019e8a0f-41c9-7c27-93c5-e237c6ad7267" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e8a0f-41c9-712c-aca0-a9208f8772e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019e8a0f-41c9-7da8-90ed-1e94284d4aaf" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e8a0f-41c9-712c-aca0-a9208f8772e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_OtherLongLivedAssets_019e8a0f-41c9-7a4e-9eab-b6e4f079fcb9" xlink:href="logi-20260630.xsd#logi_OtherLongLivedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019e8a0f-41c9-7da8-90ed-1e94284d4aaf" xlink:to="loc_logi_OtherLongLivedAssets_019e8a0f-41c9-7a4e-9eab-b6e4f079fcb9" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.logitech.com/role/SegmentInformationNarrativeDetails" xlink:type="simple" xlink:href="logi-20260630.xsd#SegmentInformationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.logitech.com/role/SegmentInformationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-75de-aa79-3d8414367bed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-7e49-a8d4-39ae53682c4f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-75de-aa79-3d8414367bed" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-7e49-a8d4-39ae53682c4f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019e8a0f-41c9-7663-9019-16b168acb167" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-7e49-a8d4-39ae53682c4f" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019e8a0f-41c9-7663-9019-16b168acb167" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019e8a0f-41c9-7663-9019-16b168acb167_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019e8a0f-41c9-7663-9019-16b168acb167" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019e8a0f-41c9-7663-9019-16b168acb167_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019e8a0f-41c9-781e-8872-06b42f9586da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019e8a0f-41c9-7663-9019-16b168acb167" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019e8a0f-41c9-781e-8872-06b42f9586da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_019e8a0f-41c9-7c02-b44d-e38bdc1da5f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeographicConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019e8a0f-41c9-781e-8872-06b42f9586da" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_019e8a0f-41c9-7c02-b44d-e38bdc1da5f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019e8a0f-41c9-7065-89de-ad93a21c6206" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-7e49-a8d4-39ae53682c4f" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019e8a0f-41c9-7065-89de-ad93a21c6206" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019e8a0f-41c9-7065-89de-ad93a21c6206_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019e8a0f-41c9-7065-89de-ad93a21c6206" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019e8a0f-41c9-7065-89de-ad93a21c6206_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019e8a0f-41c9-7560-9c30-326ca2157937" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019e8a0f-41c9-7065-89de-ad93a21c6206" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019e8a0f-41c9-7560-9c30-326ca2157937" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember_019e8a0f-41c9-7a88-9f55-0f80995516b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SalesRevenueNetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019e8a0f-41c9-7560-9c30-326ca2157937" xlink:to="loc_us-gaap_SalesRevenueNetMember_019e8a0f-41c9-7a88-9f55-0f80995516b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019e8a0f-41c9-7ceb-be87-cf05747da422" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e8a0f-41c9-7e49-a8d4-39ae53682c4f" xlink:to="loc_srt_StatementGeographicalAxis_019e8a0f-41c9-7ceb-be87-cf05747da422" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7ceb-be87-cf05747da422_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019e8a0f-41c9-7ceb-be87-cf05747da422" xlink:to="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7ceb-be87-cf05747da422_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7e90-ac09-ef856378c9a0" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019e8a0f-41c9-7ceb-be87-cf05747da422" xlink:to="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7e90-ac09-ef856378c9a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CH_019e8a0f-41c9-7a01-a6d8-0dc6dec23efe" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_CH"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7e90-ac09-ef856378c9a0" xlink:to="loc_country_CH_019e8a0f-41c9-7a01-a6d8-0dc6dec23efe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019e8a0f-41c9-72bf-88b0-6911b13e2345" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7e90-ac09-ef856378c9a0" xlink:to="loc_country_US_019e8a0f-41c9-72bf-88b0-6911b13e2345" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_019e8a0f-41c9-7592-90ab-0f6790c9d345" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e8a0f-41c9-7e90-ac09-ef856378c9a0" xlink:to="loc_country_CN_019e8a0f-41c9-7592-90ab-0f6790c9d345" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_019e8a0f-41c9-7232-a1b8-8fdc342fbd54" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-75de-aa79-3d8414367bed" xlink:to="loc_us-gaap_NumberOfOperatingSegments_019e8a0f-41c9-7232-a1b8-8fdc342fbd54" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_019e8a0f-41c9-7904-9921-9e625011d15c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-75de-aa79-3d8414367bed" xlink:to="loc_us-gaap_NumberOfReportableSegments_019e8a0f-41c9-7904-9921-9e625011d15c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019e8a0f-41c9-7b1e-83ec-2a8074f811f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-75de-aa79-3d8414367bed" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019e8a0f-41c9-7b1e-83ec-2a8074f811f3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_OtherLongLivedAssets_019e8a0f-41c9-73f8-9562-bf887abfba7a" xlink:href="logi-20260630.xsd#logi_OtherLongLivedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e8a0f-41c9-75de-aa79-3d8414367bed" xlink:to="loc_logi_OtherLongLivedAssets_019e8a0f-41c9-73f8-9562-bf887abfba7a" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#IndividualsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllIndividualsMember" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_logi_SamanthaHarnettMember_019e8a0f-4035-7c29-a423-ef0fa61ca7e4" xlink:href="logi-20260630.xsd#logi_SamanthaHarnettMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_logi_SamanthaHarnettMember_019e8a0f-4035-7c29-a423-ef0fa61ca7e4" xlink:type="arc" order="2"/>
  </link:definitionLink>
</link:linkbase>
