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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:c456b8d5-c26e-46f7-ac21-e3e6ef7a449c,g:8b00c42d-d095-4673-9795-c16953df6391-->
<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.lpcorp.com/role/CoverPage" xlink:type="simple" xlink:href="lpx-20250930.xsd#CoverPage"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/CoverPage" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitiesTable_d4b68444-1929-409c-b52d-067e3ffea1af" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntitiesTable_d4b68444-1929-409c-b52d-067e3ffea1af" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_dfd21a98-15c9-4723-9cb9-bd651db29516" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_d4b68444-1929-409c-b52d-067e3ffea1af" xlink:to="loc_dei_LegalEntityAxis_dfd21a98-15c9-4723-9cb9-bd651db29516" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_dfd21a98-15c9-4723-9cb9-bd651db29516_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_dfd21a98-15c9-4723-9cb9-bd651db29516" xlink:to="loc_dei_EntityDomain_dfd21a98-15c9-4723-9cb9-bd651db29516_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_efcc2601-448e-4b75-a9de-bd5d04056813" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_dfd21a98-15c9-4723-9cb9-bd651db29516" xlink:to="loc_dei_EntityDomain_efcc2601-448e-4b75-a9de-bd5d04056813" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_64e39167-4c88-4114-8ebe-6783c48803c8" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityIncorporationStateCountryCode_64e39167-4c88-4114-8ebe-6783c48803c8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_85cfccd6-6be4-4f87-8fe1-f311f6a99241" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_Security12bTitle_85cfccd6-6be4-4f87-8fe1-f311f6a99241" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_3d87f734-4923-4f28-9299-f07afb564f9d" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityTaxIdentificationNumber_3d87f734-4923-4f28-9299-f07afb564f9d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_ff118ec1-d263-4da1-a5f7-53cbc6275514" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_TradingSymbol_ff118ec1-d263-4da1-a5f7-53cbc6275514" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_4e9cb735-88c5-4f8f-9c53-5e4783329a3b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityRegistrantName_4e9cb735-88c5-4f8f-9c53-5e4783329a3b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_1dc7ba35-a1a9-49fc-93b5-8e9082e499f7" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityAddressAddressLine1_1dc7ba35-a1a9-49fc-93b5-8e9082e499f7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine2_99509e18-f7fb-490c-bf28-96b53b3f5580" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityAddressAddressLine2_99509e18-f7fb-490c-bf28-96b53b3f5580" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_31041bef-a9a3-4a61-b830-607894b5d770" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityAddressCityOrTown_31041bef-a9a3-4a61-b830-607894b5d770" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_a404fed1-d519-4025-b82c-211fb199b023" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityAddressStateOrProvince_a404fed1-d519-4025-b82c-211fb199b023" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_71452d45-71c5-48e6-9b4d-642cb2f06349" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityAddressPostalZipCode_71452d45-71c5-48e6-9b4d-642cb2f06349" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_01d86363-87f3-4f1b-9883-3855fea0b305" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_CityAreaCode_01d86363-87f3-4f1b-9883-3855fea0b305" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_e6a2469a-9881-4fa4-8909-2b166eb094ae" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_LocalPhoneNumber_e6a2469a-9881-4fa4-8909-2b166eb094ae" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_0811f098-dcbe-44b7-9235-b408696c0169" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityCentralIndexKey_0811f098-dcbe-44b7-9235-b408696c0169" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_d67a145e-086e-4a1c-893e-19940d6aa327" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_CurrentFiscalYearEndDate_d67a145e-086e-4a1c-893e-19940d6aa327" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_f70c15a1-620f-4c44-ad90-fc49872f0547" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_DocumentType_f70c15a1-620f-4c44-ad90-fc49872f0547" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_a34edd38-ee9e-4a0c-be3e-0b6e72b02adc" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_DocumentPeriodEndDate_a34edd38-ee9e-4a0c-be3e-0b6e72b02adc" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_fb24206c-c699-4c1e-af57-b1c9da060314" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityFileNumber_fb24206c-c699-4c1e-af57-b1c9da060314" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_424591e3-980b-4af2-becd-8226a69db138" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_DocumentFiscalYearFocus_424591e3-980b-4af2-becd-8226a69db138" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_3833fa6f-5920-4515-a342-1d28fb3c7908" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_DocumentFiscalPeriodFocus_3833fa6f-5920-4515-a342-1d28fb3c7908" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_7d4a801b-f301-47a8-9eca-2ff08df95092" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_AmendmentFlag_7d4a801b-f301-47a8-9eca-2ff08df95092" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_97130ea2-1b3e-4cb9-9277-0af61c08bb92" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_DocumentQuarterlyReport_97130ea2-1b3e-4cb9-9277-0af61c08bb92" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_0eeba10b-6f38-49a2-ac7f-415632adabba" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_DocumentTransitionReport_0eeba10b-6f38-49a2-ac7f-415632adabba" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_0c239e89-5852-472f-802f-42d478cc824f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityInteractiveDataCurrent_0c239e89-5852-472f-802f-42d478cc824f" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_f8d6bce7-ffd2-4a84-b029-dd476ea36128" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_f8d6bce7-ffd2-4a84-b029-dd476ea36128" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_2d1ec0b0-890e-4f63-8da1-16939d1fa569" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_SecurityExchangeName_2d1ec0b0-890e-4f63-8da1-16939d1fa569" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_b90e8430-a1a9-424a-b2da-3c60c8335b6e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityFilerCategory_b90e8430-a1a9-424a-b2da-3c60c8335b6e" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_d66786d7-f8dd-443c-b77d-4b51f84cfe7e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityShellCompany_d66786d7-f8dd-443c-b77d-4b51f84cfe7e" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_6a652507-20ac-4769-9376-7b8b48580452" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityEmergingGrowthCompany_6a652507-20ac-4769-9376-7b8b48580452" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_7b28b584-b528-4c85-b521-201828a083db" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntitySmallBusiness_7b28b584-b528-4c85-b521-201828a083db" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_515b6259-26c8-41e5-b2e9-6f038c18a5b0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_30afeb4b-d5c4-4d69-bd1e-4e66e3a53c40" xlink:to="loc_dei_EntityCurrentReportingStatus_515b6259-26c8-41e5-b2e9-6f038c18a5b0" xlink:type="arc" order="29"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/CondensedConsolidatedStatementsofComprehensiveIncome" xlink:type="simple" xlink:href="lpx-20250930.xsd#CondensedConsolidatedStatementsofComprehensiveIncome"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/CondensedConsolidatedStatementsofComprehensiveIncome" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_b7ab15e7-d6c7-429b-aa74-203d55005950" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_6b5ed2bc-efeb-4270-b231-c2ed03ca5dae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_b7ab15e7-d6c7-429b-aa74-203d55005950" xlink:to="loc_us-gaap_StatementTable_6b5ed2bc-efeb-4270-b231-c2ed03ca5dae" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_9fdcb748-05f6-4cf3-ba8b-85547e93dec7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_6b5ed2bc-efeb-4270-b231-c2ed03ca5dae" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_9fdcb748-05f6-4cf3-ba8b-85547e93dec7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_9fdcb748-05f6-4cf3-ba8b-85547e93dec7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_9fdcb748-05f6-4cf3-ba8b-85547e93dec7" xlink:to="loc_us-gaap_EquityComponentDomain_9fdcb748-05f6-4cf3-ba8b-85547e93dec7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_875c274f-4e5b-464e-b671-b0fe36c1a2e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_9fdcb748-05f6-4cf3-ba8b-85547e93dec7" xlink:to="loc_us-gaap_EquityComponentDomain_875c274f-4e5b-464e-b671-b0fe36c1a2e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_f69c1150-4fb0-4b89-af50-6a0658cdffd5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_875c274f-4e5b-464e-b671-b0fe36c1a2e0" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_f69c1150-4fb0-4b89-af50-6a0658cdffd5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_bd9079d8-2f94-4cc2-a64a-c2dc78d6acdb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7ab15e7-d6c7-429b-aa74-203d55005950" xlink:to="loc_us-gaap_ProfitLoss_bd9079d8-2f94-4cc2-a64a-c2dc78d6acdb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_c1b92b73-de8d-41a1-902e-e11853687448" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7ab15e7-d6c7-429b-aa74-203d55005950" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_c1b92b73-de8d-41a1-902e-e11853687448" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_d9c6fe4c-b70e-4fc7-980c-1aa202dc4af7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_c1b92b73-de8d-41a1-902e-e11853687448" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_d9c6fe4c-b70e-4fc7-980c-1aa202dc4af7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_d622ccd2-3dbb-448e-86eb-dc5df464cf67" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b7ab15e7-d6c7-429b-aa74-203d55005950" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_d622ccd2-3dbb-448e-86eb-dc5df464cf67" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/CondensedConsolidatedStatementsofStockholdersEquity" xlink:type="simple" xlink:href="lpx-20250930.xsd#CondensedConsolidatedStatementsofStockholdersEquity"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/CondensedConsolidatedStatementsofStockholdersEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_805489a2-62a5-4eea-b31f-ff8ea612d0cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_eb74fb6a-d0a7-4cbf-b1b2-95e5de76a127" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_805489a2-62a5-4eea-b31f-ff8ea612d0cd" xlink:to="loc_us-gaap_StatementTable_eb74fb6a-d0a7-4cbf-b1b2-95e5de76a127" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_05b3cdfc-06d7-4bf7-aed1-0aebcfbbcc1b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_eb74fb6a-d0a7-4cbf-b1b2-95e5de76a127" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_05b3cdfc-06d7-4bf7-aed1-0aebcfbbcc1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_05b3cdfc-06d7-4bf7-aed1-0aebcfbbcc1b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_05b3cdfc-06d7-4bf7-aed1-0aebcfbbcc1b" xlink:to="loc_us-gaap_EquityComponentDomain_05b3cdfc-06d7-4bf7-aed1-0aebcfbbcc1b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_3faf5049-22ff-4500-b833-42ae1bb298f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_05b3cdfc-06d7-4bf7-aed1-0aebcfbbcc1b" xlink:to="loc_us-gaap_EquityComponentDomain_3faf5049-22ff-4500-b833-42ae1bb298f0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_ef3882d3-0595-4a80-83e1-86df65397edc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3faf5049-22ff-4500-b833-42ae1bb298f0" xlink:to="loc_us-gaap_CommonStockMember_ef3882d3-0595-4a80-83e1-86df65397edc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_ca5cfaea-e892-44a6-9024-97054b61c1cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3faf5049-22ff-4500-b833-42ae1bb298f0" xlink:to="loc_us-gaap_TreasuryStockCommonMember_ca5cfaea-e892-44a6-9024-97054b61c1cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_fd96d8fd-6d5a-4e7b-aeb7-cfd3a428dd82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3faf5049-22ff-4500-b833-42ae1bb298f0" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_fd96d8fd-6d5a-4e7b-aeb7-cfd3a428dd82" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_0a0a5d33-89e5-4286-b03e-8dfa79c763b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3faf5049-22ff-4500-b833-42ae1bb298f0" xlink:to="loc_us-gaap_RetainedEarningsMember_0a0a5d33-89e5-4286-b03e-8dfa79c763b4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_dd1eec13-eb42-4b58-a55b-9988bb925f91" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3faf5049-22ff-4500-b833-42ae1bb298f0" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_dd1eec13-eb42-4b58-a55b-9988bb925f91" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_805489a2-62a5-4eea-b31f-ff8ea612d0cd" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_5d308d8b-4121-40c4-9736-eb41524ca03d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_5d308d8b-4121-40c4-9736-eb41524ca03d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_557e6b79-9e80-4534-8c5d-a539c5bf54a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_us-gaap_TreasuryStockCommonShares_557e6b79-9e80-4534-8c5d-a539c5bf54a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_04c6994a-8824-4ca4-b179-3474755dfe0e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_us-gaap_StockholdersEquity_04c6994a-8824-4ca4-b179-3474755dfe0e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_915fc922-63cd-4ea0-92a3-c736f1472771" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_us-gaap_NetIncomeLoss_915fc922-63cd-4ea0-92a3-c736f1472771" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividends_fb9a2681-8a29-4c6b-affe-bc86c63341bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_us-gaap_PaymentsOfDividends_fb9a2681-8a29-4c6b-affe-bc86c63341bf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_854358de-b2ad-4ad3-a7ac-e92c91c4460f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_854358de-b2ad-4ad3-a7ac-e92c91c4460f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_8c2b9893-f29a-42b3-b424-0e1157855b98" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_8c2b9893-f29a-42b3-b424-0e1157855b98" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_CommonstockSharesacquired_0f967694-20ac-4f6f-9bbe-426dc87e3e0a" xlink:href="lpx-20250930.xsd#lpx_CommonstockSharesacquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_lpx_CommonstockSharesacquired_0f967694-20ac-4f6f-9bbe-426dc87e3e0a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_CommonstockValueSharesacquired_cc7384dc-30fd-4d6a-b894-09da91c31115" xlink:href="lpx-20250930.xsd#lpx_CommonstockValueSharesacquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_lpx_CommonstockValueSharesacquired_cc7384dc-30fd-4d6a-b894-09da91c31115" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_d4c9a4ed-2303-4814-b923-04a9b95d9ab8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_d4c9a4ed-2303-4814-b923-04a9b95d9ab8" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_a5257c08-1f51-4dbe-9be8-766b5ab4fc9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0d5a278e-3a2a-4a1e-a693-2730c79d8169" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_a5257c08-1f51-4dbe-9be8-766b5ab4fc9a" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_04fe7c9c-2631-4fa2-943f-7ef32203454f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_ec1d06b4-e274-410a-8d26-cd5d7735228e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_0fe2a34f-1f86-473a-9e48-8e06d90dc40f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonShares"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/RevenueDetails" xlink:type="simple" xlink:href="lpx-20250930.xsd#RevenueDetails"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/RevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_3f54343a-16ea-4729-b533-a8b7b924abee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_8b854205-e42d-4138-99d3-7655a424bf61" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_3f54343a-16ea-4729-b533-a8b7b924abee" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_8b854205-e42d-4138-99d3-7655a424bf61" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_ProducttypeAxis_eb7428f2-8f7b-4e8e-8bc2-442fa08dc98e" xlink:href="lpx-20250930.xsd#lpx_ProducttypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_8b854205-e42d-4138-99d3-7655a424bf61" xlink:to="loc_lpx_ProducttypeAxis_eb7428f2-8f7b-4e8e-8bc2-442fa08dc98e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_ProducttypeDomain_eb7428f2-8f7b-4e8e-8bc2-442fa08dc98e_default" xlink:href="lpx-20250930.xsd#lpx_ProducttypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_lpx_ProducttypeAxis_eb7428f2-8f7b-4e8e-8bc2-442fa08dc98e" xlink:to="loc_lpx_ProducttypeDomain_eb7428f2-8f7b-4e8e-8bc2-442fa08dc98e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_ProducttypeDomain_00061575-0d07-4f9d-af77-8ff5bbbdc398" xlink:href="lpx-20250930.xsd#lpx_ProducttypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_lpx_ProducttypeAxis_eb7428f2-8f7b-4e8e-8bc2-442fa08dc98e" xlink:to="loc_lpx_ProducttypeDomain_00061575-0d07-4f9d-af77-8ff5bbbdc398" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_ValueaddMember_0bc3813a-ea89-4105-8eb7-fe1b22a7807d" xlink:href="lpx-20250930.xsd#lpx_ValueaddMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lpx_ProducttypeDomain_00061575-0d07-4f9d-af77-8ff5bbbdc398" xlink:to="loc_lpx_ValueaddMember_0bc3813a-ea89-4105-8eb7-fe1b22a7807d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_CommodityProductsMember_be0c0498-aaaf-4840-9e41-4d610c49ded0" xlink:href="lpx-20250930.xsd#lpx_CommodityProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lpx_ProducttypeDomain_00061575-0d07-4f9d-af77-8ff5bbbdc398" xlink:to="loc_lpx_CommodityProductsMember_be0c0498-aaaf-4840-9e41-4d610c49ded0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_OtherProductTypesMember_54231779-5425-477e-9836-786f31458943" xlink:href="lpx-20250930.xsd#lpx_OtherProductTypesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_lpx_ProducttypeDomain_00061575-0d07-4f9d-af77-8ff5bbbdc398" xlink:to="loc_lpx_OtherProductTypesMember_54231779-5425-477e-9836-786f31458943" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_cad1143f-028d-4283-8b10-1412c1a7ee24" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_8b854205-e42d-4138-99d3-7655a424bf61" xlink:to="loc_srt_ProductOrServiceAxis_cad1143f-028d-4283-8b10-1412c1a7ee24" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_cad1143f-028d-4283-8b10-1412c1a7ee24_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_cad1143f-028d-4283-8b10-1412c1a7ee24" xlink:to="loc_srt_ProductsAndServicesDomain_cad1143f-028d-4283-8b10-1412c1a7ee24_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_6a5cabec-8ecd-41e4-9c6a-ba4f63fa42e9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_cad1143f-028d-4283-8b10-1412c1a7ee24" xlink:to="loc_srt_ProductsAndServicesDomain_6a5cabec-8ecd-41e4-9c6a-ba4f63fa42e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_SmartSideStrandsidingMember_ae043b87-6aab-42d9-a495-e3f70d4a566c" xlink:href="lpx-20250930.xsd#lpx_SmartSideStrandsidingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_6a5cabec-8ecd-41e4-9c6a-ba4f63fa42e9" xlink:to="loc_lpx_SmartSideStrandsidingMember_ae043b87-6aab-42d9-a495-e3f70d4a566c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_OSBvalueaddMember_27bd9929-4c8d-408c-826d-a135f8151d5e" xlink:href="lpx-20250930.xsd#lpx_OSBvalueaddMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_6a5cabec-8ecd-41e4-9c6a-ba4f63fa42e9" xlink:to="loc_lpx_OSBvalueaddMember_27bd9929-4c8d-408c-826d-a135f8151d5e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_OSBcommodityMember_152153c9-f32c-4409-bc74-cdcbd77a0dd5" xlink:href="lpx-20250930.xsd#lpx_OSBcommodityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_6a5cabec-8ecd-41e4-9c6a-ba4f63fa42e9" xlink:to="loc_lpx_OSBcommodityMember_152153c9-f32c-4409-bc74-cdcbd77a0dd5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_OtherproductsMember_e32be717-7d0d-4649-9f83-aded00d8ba31" xlink:href="lpx-20250930.xsd#lpx_OtherproductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_6a5cabec-8ecd-41e4-9c6a-ba4f63fa42e9" xlink:to="loc_lpx_OtherproductsMember_e32be717-7d0d-4649-9f83-aded00d8ba31" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_89c1a56f-a2e1-42bd-8b90-d12cd57ad47e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_8b854205-e42d-4138-99d3-7655a424bf61" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_89c1a56f-a2e1-42bd-8b90-d12cd57ad47e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_89c1a56f-a2e1-42bd-8b90-d12cd57ad47e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_89c1a56f-a2e1-42bd-8b90-d12cd57ad47e" xlink:to="loc_us-gaap_SegmentDomain_89c1a56f-a2e1-42bd-8b90-d12cd57ad47e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_6902d997-ae8a-42b4-8b4c-1b22d7493549" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_89c1a56f-a2e1-42bd-8b90-d12cd57ad47e" xlink:to="loc_us-gaap_SegmentDomain_6902d997-ae8a-42b4-8b4c-1b22d7493549" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_SidingSegmentMember_e9ffb1ff-c18d-4c01-b024-6194c5a876a5" xlink:href="lpx-20250930.xsd#lpx_SidingSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6902d997-ae8a-42b4-8b4c-1b22d7493549" xlink:to="loc_lpx_SidingSegmentMember_e9ffb1ff-c18d-4c01-b024-6194c5a876a5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_OSBSegmentMember_c9819500-ddf8-48f2-ac7f-47bc3858c8d4" xlink:href="lpx-20250930.xsd#lpx_OSBSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6902d997-ae8a-42b4-8b4c-1b22d7493549" xlink:to="loc_lpx_OSBSegmentMember_c9819500-ddf8-48f2-ac7f-47bc3858c8d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_LPSouthAmericaSegmentMember_5cfbb6ae-31e6-429a-8a7b-875b78d25640" xlink:href="lpx-20250930.xsd#lpx_LPSouthAmericaSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6902d997-ae8a-42b4-8b4c-1b22d7493549" xlink:to="loc_lpx_LPSouthAmericaSegmentMember_5cfbb6ae-31e6-429a-8a7b-875b78d25640" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllOtherSegmentsMember_8c36fc18-104f-4101-ba9a-029b3637cacb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllOtherSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6902d997-ae8a-42b4-8b4c-1b22d7493549" xlink:to="loc_us-gaap_AllOtherSegmentsMember_8c36fc18-104f-4101-ba9a-029b3637cacb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_b21cd46e-4600-4f8e-863f-70738b00e326" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_3f54343a-16ea-4729-b533-a8b7b924abee" xlink:to="loc_us-gaap_Revenues_b21cd46e-4600-4f8e-863f-70738b00e326" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/SupplementalBalanceSheetInformationScheduleofPropertyPlantandEquipmentDetails" xlink:type="simple" xlink:href="lpx-20250930.xsd#SupplementalBalanceSheetInformationScheduleofPropertyPlantandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/SupplementalBalanceSheetInformationScheduleofPropertyPlantandEquipmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2226a555-6a3c-420b-868c-7c93f53f5beb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_c349853c-7f4f-42ac-9ee3-5c5e8e2c842d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2226a555-6a3c-420b-868c-7c93f53f5beb" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_c349853c-7f4f-42ac-9ee3-5c5e8e2c842d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3d76b85a-6ea0-4af3-881c-4580d5ce05bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_c349853c-7f4f-42ac-9ee3-5c5e8e2c842d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3d76b85a-6ea0-4af3-881c-4580d5ce05bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3d76b85a-6ea0-4af3-881c-4580d5ce05bc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3d76b85a-6ea0-4af3-881c-4580d5ce05bc" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3d76b85a-6ea0-4af3-881c-4580d5ce05bc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b5684056-ef0e-4911-96b4-255018114cdc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3d76b85a-6ea0-4af3-881c-4580d5ce05bc" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b5684056-ef0e-4911-96b4-255018114cdc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_LandLandImprovementsAndLoggingRoadsNetMember_b1c239dd-fb5a-46ef-bb1f-3eea4d3eb5f4" xlink:href="lpx-20250930.xsd#lpx_LandLandImprovementsAndLoggingRoadsNetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b5684056-ef0e-4911-96b4-255018114cdc" xlink:to="loc_lpx_LandLandImprovementsAndLoggingRoadsNetMember_b1c239dd-fb5a-46ef-bb1f-3eea4d3eb5f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingMember_2de4cce6-6514-43ac-b1de-eb1a06810d2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b5684056-ef0e-4911-96b4-255018114cdc" xlink:to="loc_us-gaap_BuildingMember_2de4cce6-6514-43ac-b1de-eb1a06810d2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_bcb54d25-864f-4952-b2e4-0813b51f2d7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b5684056-ef0e-4911-96b4-255018114cdc" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_bcb54d25-864f-4952-b2e4-0813b51f2d7b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_d2d69d5e-4ac1-4743-b931-96b27e4fdecb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_b5684056-ef0e-4911-96b4-255018114cdc" xlink:to="loc_us-gaap_ConstructionInProgressMember_d2d69d5e-4ac1-4743-b931-96b27e4fdecb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_6e1377fe-cf82-409d-9ee9-a77af72596e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2226a555-6a3c-420b-868c-7c93f53f5beb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_6e1377fe-cf82-409d-9ee9-a77af72596e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_f1f8cc75-d06b-48d8-8317-13e88c59c603" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2226a555-6a3c-420b-868c-7c93f53f5beb" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_f1f8cc75-d06b-48d8-8317-13e88c59c603" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_fa6b7b1a-b94c-40c5-a4a7-cc450ad66b50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2226a555-6a3c-420b-868c-7c93f53f5beb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_fa6b7b1a-b94c-40c5-a4a7-cc450ad66b50" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/SupplementalBalanceSheetInformationScheduleofOtherLongTermLiabilitiesDetails" xlink:type="simple" xlink:href="lpx-20250930.xsd#SupplementalBalanceSheetInformationScheduleofOtherLongTermLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/SupplementalBalanceSheetInformationScheduleofOtherLongTermLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_0c6ffb98-f3c6-40e5-b2dd-821316c0ee76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_64f09ad8-c244-4cbb-8f1a-cd7d94cd15fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_0c6ffb98-f3c6-40e5-b2dd-821316c0ee76" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_64f09ad8-c244-4cbb-8f1a-cd7d94cd15fe" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_696aed6c-99b1-443d-b52e-e72afe13c0c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_64f09ad8-c244-4cbb-8f1a-cd7d94cd15fe" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_696aed6c-99b1-443d-b52e-e72afe13c0c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_696aed6c-99b1-443d-b52e-e72afe13c0c0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_696aed6c-99b1-443d-b52e-e72afe13c0c0" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_696aed6c-99b1-443d-b52e-e72afe13c0c0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_72da5499-f776-4f97-9286-275e11b5214d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_696aed6c-99b1-443d-b52e-e72afe13c0c0" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_72da5499-f776-4f97-9286-275e11b5214d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_a19ab3b6-2ca3-494b-8bbc-0f49a23f2b16" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_72da5499-f776-4f97-9286-275e11b5214d" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_a19ab3b6-2ca3-494b-8bbc-0f49a23f2b16" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_ca2e05b3-bcd5-4ff6-b3db-1152962a0b58" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_72da5499-f776-4f97-9286-275e11b5214d" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_ca2e05b3-bcd5-4ff6-b3db-1152962a0b58" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_d540b194-f5b0-4f87-8a2c-4a63dd1fdbec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_0c6ffb98-f3c6-40e5-b2dd-821316c0ee76" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligation_d540b194-f5b0-4f87-8a2c-4a63dd1fdbec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationsNoncurrent_407e2bbf-7b38-47b8-b2be-634a88175642" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetRetirementObligationsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_0c6ffb98-f3c6-40e5-b2dd-821316c0ee76" xlink:to="loc_us-gaap_AssetRetirementObligationsNoncurrent_407e2bbf-7b38-47b8-b2be-634a88175642" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_c0074d74-d334-49ea-9593-1246d8f2172b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilityForUncertainTaxPositionsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_0c6ffb98-f3c6-40e5-b2dd-821316c0ee76" xlink:to="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_c0074d74-d334-49ea-9593-1246d8f2172b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductWarrantyAccrualNoncurrent_fe457cd8-dbb4-4519-85f4-f7e2a4acdc2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProductWarrantyAccrualNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_0c6ffb98-f3c6-40e5-b2dd-821316c0ee76" xlink:to="loc_us-gaap_ProductWarrantyAccrualNoncurrent_fe457cd8-dbb4-4519-85f4-f7e2a4acdc2d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherSundryLiabilitiesNoncurrent_fc965d2f-f48e-47d9-b816-7ba676b1f75f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherSundryLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_0c6ffb98-f3c6-40e5-b2dd-821316c0ee76" xlink:to="loc_us-gaap_OtherSundryLiabilitiesNoncurrent_fc965d2f-f48e-47d9-b816-7ba676b1f75f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_b80a2c45-83ee-403a-abfd-70523a1d54c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_0c6ffb98-f3c6-40e5-b2dd-821316c0ee76" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_b80a2c45-83ee-403a-abfd-70523a1d54c8" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/FairValueMeasurementsDetails" xlink:type="simple" xlink:href="lpx-20250930.xsd#FairValueMeasurementsDetails"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/FairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8cff7e83-c0dd-4afc-9aed-aab6382589ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ed761fe1-5862-4632-b8b5-445c58f489ea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8cff7e83-c0dd-4afc-9aed-aab6382589ae" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ed761fe1-5862-4632-b8b5-445c58f489ea" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_af44c1ab-f2e7-40af-a646-b622fe90a0da" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ed761fe1-5862-4632-b8b5-445c58f489ea" xlink:to="loc_us-gaap_DebtInstrumentAxis_af44c1ab-f2e7-40af-a646-b622fe90a0da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_af44c1ab-f2e7-40af-a646-b622fe90a0da_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_af44c1ab-f2e7-40af-a646-b622fe90a0da" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_af44c1ab-f2e7-40af-a646-b622fe90a0da_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_29b2fa7f-d532-44fc-bfc1-86182baca30b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_af44c1ab-f2e7-40af-a646-b622fe90a0da" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_29b2fa7f-d532-44fc-bfc1-86182baca30b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_SeniorUnsecuredNotesMaturing2029Member_bbb62f9d-68ac-4ef4-bb42-9e6a9b582707" xlink:href="lpx-20250930.xsd#lpx_SeniorUnsecuredNotesMaturing2029Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_29b2fa7f-d532-44fc-bfc1-86182baca30b" xlink:to="loc_lpx_SeniorUnsecuredNotesMaturing2029Member_bbb62f9d-68ac-4ef4-bb42-9e6a9b582707" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_AmendedCreditFacilityMember_a5b4bb52-14de-431a-b713-3486910d0abf" xlink:href="lpx-20250930.xsd#lpx_AmendedCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_29b2fa7f-d532-44fc-bfc1-86182baca30b" xlink:to="loc_lpx_AmendedCreditFacilityMember_a5b4bb52-14de-431a-b713-3486910d0abf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_75e0285f-e10f-4c11-a7ea-33e06369723b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ed761fe1-5862-4632-b8b5-445c58f489ea" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_75e0285f-e10f-4c11-a7ea-33e06369723b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_75e0285f-e10f-4c11-a7ea-33e06369723b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_75e0285f-e10f-4c11-a7ea-33e06369723b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_75e0285f-e10f-4c11-a7ea-33e06369723b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_35e09b60-c611-4f40-8702-9827a3fb8abe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_75e0285f-e10f-4c11-a7ea-33e06369723b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_35e09b60-c611-4f40-8702-9827a3fb8abe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_52140cc3-2a76-41e7-85b8-deba1e0bf3f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_35e09b60-c611-4f40-8702-9827a3fb8abe" xlink:to="loc_us-gaap_SeniorNotesMember_52140cc3-2a76-41e7-85b8-deba1e0bf3f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_SeniorUnsecuredNotesMaturing2029Member_3dd8d501-1290-4d2b-9e9f-15e6f95ce685" xlink:href="lpx-20250930.xsd#lpx_SeniorUnsecuredNotesMaturing2029Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_35e09b60-c611-4f40-8702-9827a3fb8abe" xlink:to="loc_lpx_SeniorUnsecuredNotesMaturing2029Member_3dd8d501-1290-4d2b-9e9f-15e6f95ce685" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_a8c56320-dbbc-4f66-b96c-fda000e65b1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_35e09b60-c611-4f40-8702-9827a3fb8abe" xlink:to="loc_us-gaap_LineOfCreditMember_a8c56320-dbbc-4f66-b96c-fda000e65b1d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_LetterOfCreditSubLimitMember_fc142401-d014-4fa8-87b3-fd23b6b40aca" xlink:href="lpx-20250930.xsd#lpx_LetterOfCreditSubLimitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_35e09b60-c611-4f40-8702-9827a3fb8abe" xlink:to="loc_lpx_LetterOfCreditSubLimitMember_fc142401-d014-4fa8-87b3-fd23b6b40aca" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_69f6583c-eeba-43bc-94cf-bca49255fe41" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_ed761fe1-5862-4632-b8b5-445c58f489ea" xlink:to="loc_us-gaap_CreditFacilityAxis_69f6583c-eeba-43bc-94cf-bca49255fe41" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_69f6583c-eeba-43bc-94cf-bca49255fe41_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_69f6583c-eeba-43bc-94cf-bca49255fe41" xlink:to="loc_us-gaap_CreditFacilityDomain_69f6583c-eeba-43bc-94cf-bca49255fe41_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_49b29377-f5e9-46a9-8828-a627b0220a9d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_69f6583c-eeba-43bc-94cf-bca49255fe41" xlink:to="loc_us-gaap_CreditFacilityDomain_49b29377-f5e9-46a9-8828-a627b0220a9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_328ef2f1-039e-4aa7-9e31-45295cdadd76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_49b29377-f5e9-46a9-8828-a627b0220a9d" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_328ef2f1-039e-4aa7-9e31-45295cdadd76" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_22fbc2f4-58f0-434b-a88b-d1d084565d52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8cff7e83-c0dd-4afc-9aed-aab6382589ae" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_22fbc2f4-58f0-434b-a88b-d1d084565d52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_6043539a-256d-4711-a332-f844bf7afba8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8cff7e83-c0dd-4afc-9aed-aab6382589ae" xlink:to="loc_us-gaap_LongTermDebt_6043539a-256d-4711-a332-f844bf7afba8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_d4f7f7a1-7391-4171-9d11-9b9a29284d64" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8cff7e83-c0dd-4afc-9aed-aab6382589ae" xlink:to="loc_us-gaap_LongTermDebtFairValue_d4f7f7a1-7391-4171-9d11-9b9a29284d64" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_97f85669-a2c6-42dd-b5e5-e5e78628c59b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8cff7e83-c0dd-4afc-9aed-aab6382589ae" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_97f85669-a2c6-42dd-b5e5-e5e78628c59b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_7baa9c68-3738-4499-8e33-fef3279cd9a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8cff7e83-c0dd-4afc-9aed-aab6382589ae" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_7baa9c68-3738-4499-8e33-fef3279cd9a1" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/GoodwillandOtherIntangibleAssetsDetails" xlink:type="simple" xlink:href="lpx-20250930.xsd#GoodwillandOtherIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/GoodwillandOtherIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_d0ef836c-eae0-41c4-898e-06e801915f04" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_399bd8e6-d345-4be2-a269-fa063dee40cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_d0ef836c-eae0-41c4-898e-06e801915f04" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_399bd8e6-d345-4be2-a269-fa063dee40cb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_913fc212-d68e-4073-948c-bacdf3ef64f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_399bd8e6-d345-4be2-a269-fa063dee40cb" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_913fc212-d68e-4073-948c-bacdf3ef64f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_913fc212-d68e-4073-948c-bacdf3ef64f3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_913fc212-d68e-4073-948c-bacdf3ef64f3" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_913fc212-d68e-4073-948c-bacdf3ef64f3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d5d58171-276f-494c-8b49-e6edc4af9885" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_913fc212-d68e-4073-948c-bacdf3ef64f3" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d5d58171-276f-494c-8b49-e6edc4af9885" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LicenseMember_ff6c2471-5914-45d4-abff-24e13ee71f8b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LicenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d5d58171-276f-494c-8b49-e6edc4af9885" xlink:to="loc_us-gaap_LicenseMember_ff6c2471-5914-45d4-abff-24e13ee71f8b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_3f6c0878-5f59-4ef2-8860-2f27834fd8bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d5d58171-276f-494c-8b49-e6edc4af9885" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_3f6c0878-5f59-4ef2-8860-2f27834fd8bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimberAndTimberlands_b6cb7025-64e3-4a58-a797-3d052ebbf352" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TimberAndTimberlands"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_d0ef836c-eae0-41c4-898e-06e801915f04" xlink:to="loc_us-gaap_TimberAndTimberlands_b6cb7025-64e3-4a58-a797-3d052ebbf352" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_60946793-ac9d-4450-a53e-92a18198a2b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_d0ef836c-eae0-41c4-898e-06e801915f04" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_60946793-ac9d-4450-a53e-92a18198a2b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_7289cd20-c001-44a6-b436-31a8a7b1cd04" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_d0ef836c-eae0-41c4-898e-06e801915f04" xlink:to="loc_us-gaap_Goodwill_7289cd20-c001-44a6-b436-31a8a7b1cd04" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_b16b9cd5-18ee-4bfd-9a30-4f8963d0c931" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_d0ef836c-eae0-41c4-898e-06e801915f04" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_b16b9cd5-18ee-4bfd-9a30-4f8963d0c931" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_e300943e-e20f-4934-9555-0e8f16e76d06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_d0ef836c-eae0-41c4-898e-06e801915f04" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_e300943e-e20f-4934-9555-0e8f16e76d06" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/ImpairmentsofLongLivedAssetsDetails" xlink:type="simple" xlink:href="lpx-20250930.xsd#ImpairmentsofLongLivedAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/ImpairmentsofLongLivedAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedLineItems_2d120e19-ae0c-4073-b101-1f94f4983552" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairedLongLivedAssetsHeldAndUsedLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfImpairedLongLivedAssetsHeldAndUsedTable_70f24d44-30e0-4253-9b5a-30340b268403" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfImpairedLongLivedAssetsHeldAndUsedTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedLineItems_2d120e19-ae0c-4073-b101-1f94f4983552" xlink:to="loc_us-gaap_ScheduleOfImpairedLongLivedAssetsHeldAndUsedTable_70f24d44-30e0-4253-9b5a-30340b268403" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis_070f8481-a633-4dce-bba2-e66051afcea4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfImpairedLongLivedAssetsHeldAndUsedTable_70f24d44-30e0-4253-9b5a-30340b268403" xlink:to="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis_070f8481-a633-4dce-bba2-e66051afcea4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedAssetNameDomain_070f8481-a633-4dce-bba2-e66051afcea4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairedLongLivedAssetsHeldAndUsedAssetNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis_070f8481-a633-4dce-bba2-e66051afcea4" xlink:to="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedAssetNameDomain_070f8481-a633-4dce-bba2-e66051afcea4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedAssetNameDomain_d78439ad-7b40-43a5-a590-4c10bf768d8d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairedLongLivedAssetsHeldAndUsedAssetNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis_070f8481-a633-4dce-bba2-e66051afcea4" xlink:to="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedAssetNameDomain_d78439ad-7b40-43a5-a590-4c10bf768d8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentMember_b0961a65-13e2-4ca6-b848-345515745037" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedAssetNameDomain_d78439ad-7b40-43a5-a590-4c10bf768d8d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentMember_b0961a65-13e2-4ca6-b848-345515745037" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetImpairmentCharges_29f588a4-b0b7-4dc9-abea-662aba73af39" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedLineItems_2d120e19-ae0c-4073-b101-1f94f4983552" xlink:to="loc_us-gaap_AssetImpairmentCharges_29f588a4-b0b7-4dc9-abea-662aba73af39" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TangibleAssetImpairmentCharges_8ef8e65f-34a5-4b2a-b67a-132a8c27a332" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TangibleAssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedLineItems_2d120e19-ae0c-4073-b101-1f94f4983552" xlink:to="loc_us-gaap_TangibleAssetImpairmentCharges_8ef8e65f-34a5-4b2a-b67a-132a8c27a332" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLeasehold_d2fd1edf-67fa-4038-b3ba-042df05ff4a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOfLeasehold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedLineItems_2d120e19-ae0c-4073-b101-1f94f4983552" xlink:to="loc_us-gaap_ImpairmentOfLeasehold_d2fd1edf-67fa-4038-b3ba-042df05ff4a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseImpairmentLoss_a34b63bc-ab39-4b52-bbfb-8e7b46e95e99" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ImpairedLongLivedAssetsHeldAndUsedLineItems_2d120e19-ae0c-4073-b101-1f94f4983552" xlink:to="loc_us-gaap_OperatingLeaseImpairmentLoss_a34b63bc-ab39-4b52-bbfb-8e7b46e95e99" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/CommitmentsandContingenciesDetails" xlink:type="simple" xlink:href="lpx-20250930.xsd#CommitmentsandContingenciesDetails"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/CommitmentsandContingenciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_511e5060-f7f3-40a7-a971-92799c7c6944" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_3a7f58ba-c2c3-4aa7-b578-5ec2416edfed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_511e5060-f7f3-40a7-a971-92799c7c6944" xlink:to="loc_us-gaap_LossContingenciesTable_3a7f58ba-c2c3-4aa7-b578-5ec2416edfed" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_bf1fe549-f7fd-4387-882d-7ef39c54b243" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_3a7f58ba-c2c3-4aa7-b578-5ec2416edfed" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_bf1fe549-f7fd-4387-882d-7ef39c54b243" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_bf1fe549-f7fd-4387-882d-7ef39c54b243_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_bf1fe549-f7fd-4387-882d-7ef39c54b243" xlink:to="loc_us-gaap_LossContingencyNatureDomain_bf1fe549-f7fd-4387-882d-7ef39c54b243_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_2251746f-c0ff-4a5a-8d1f-300d3c377118" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_bf1fe549-f7fd-4387-882d-7ef39c54b243" xlink:to="loc_us-gaap_LossContingencyNatureDomain_2251746f-c0ff-4a5a-8d1f-300d3c377118" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReserveForEnvironmentalCostsMember_2e483f7e-57cb-4c65-9ebf-6f99d1063e95" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReserveForEnvironmentalCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_2251746f-c0ff-4a5a-8d1f-300d3c377118" xlink:to="loc_us-gaap_ReserveForEnvironmentalCostsMember_2e483f7e-57cb-4c65-9ebf-6f99d1063e95" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_1bd95399-ee1c-4f79-a2a9-326585fad484" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_511e5060-f7f3-40a7-a971-92799c7c6944" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_1bd95399-ee1c-4f79-a2a9-326585fad484" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesGross_f9f5d8fa-da16-4af9-a335-2df438632fd6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_511e5060-f7f3-40a7-a971-92799c7c6944" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesGross_f9f5d8fa-da16-4af9-a335-2df438632fd6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualCarryingValueCurrent_31a0ccb8-281d-4fd3-8cbb-e8aad49c095d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyAccrualCarryingValueCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_511e5060-f7f3-40a7-a971-92799c7c6944" xlink:to="loc_us-gaap_LossContingencyAccrualCarryingValueCurrent_31a0ccb8-281d-4fd3-8cbb-e8aad49c095d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualCarryingValueNoncurrent_e2e09f55-f817-462e-a570-fe44699dfce6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyAccrualCarryingValueNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_511e5060-f7f3-40a7-a971-92799c7c6944" xlink:to="loc_us-gaap_LossContingencyAccrualCarryingValueNoncurrent_e2e09f55-f817-462e-a570-fe44699dfce6" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/AccumulatedComprehensiveLossDetails" xlink:type="simple" xlink:href="lpx-20250930.xsd#AccumulatedComprehensiveLossDetails"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/AccumulatedComprehensiveLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_dc50c1eb-1d01-4d84-853d-6bc72c52bb02" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_b23a97a6-b9e3-47cd-8508-11f76a85984f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_dc50c1eb-1d01-4d84-853d-6bc72c52bb02" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_b23a97a6-b9e3-47cd-8508-11f76a85984f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_94575cd5-992d-4a2a-8887-e4750c923222" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_b23a97a6-b9e3-47cd-8508-11f76a85984f" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_94575cd5-992d-4a2a-8887-e4750c923222" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_94575cd5-992d-4a2a-8887-e4750c923222_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_94575cd5-992d-4a2a-8887-e4750c923222" xlink:to="loc_us-gaap_EquityComponentDomain_94575cd5-992d-4a2a-8887-e4750c923222_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_03adb98d-b3c2-41a7-a167-4df15c0648bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_94575cd5-992d-4a2a-8887-e4750c923222" xlink:to="loc_us-gaap_EquityComponentDomain_03adb98d-b3c2-41a7-a167-4df15c0648bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_acc78acf-bc1a-4907-a56d-ebccad8fc254" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_03adb98d-b3c2-41a7-a167-4df15c0648bf" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_acc78acf-bc1a-4907-a56d-ebccad8fc254" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_123f40d9-df2b-4578-b44b-8465526e3a50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_acc78acf-bc1a-4907-a56d-ebccad8fc254" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_123f40d9-df2b-4578-b44b-8465526e3a50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_67fb9687-8bdc-4409-b28e-f040ec03c9f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_dc50c1eb-1d01-4d84-853d-6bc72c52bb02" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_67fb9687-8bdc-4409-b28e-f040ec03c9f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_2823a7be-2c32-438c-bf91-559d12df14dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_67fb9687-8bdc-4409-b28e-f040ec03c9f9" xlink:to="loc_us-gaap_StockholdersEquity_2823a7be-2c32-438c-bf91-559d12df14dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_8a4a2c5c-17f0-441c-b1ce-8ee5f4fec29e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_67fb9687-8bdc-4409-b28e-f040ec03c9f9" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_8a4a2c5c-17f0-441c-b1ce-8ee5f4fec29e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_6f2f3cc5-3c7b-4b4e-ad76-5458c9db4e62" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/SelectedSegmentDataScheduleofSegmentReportingInformationbySegmentDetails" xlink:type="simple" xlink:href="lpx-20250930.xsd#SelectedSegmentDataScheduleofSegmentReportingInformationbySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/SelectedSegmentDataScheduleofSegmentReportingInformationbySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_fd3d0aeb-a3fc-4cd2-8408-2cf7fe1aaab1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_db17c571-4578-4afa-8c9f-30fa59a69666" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_fd3d0aeb-a3fc-4cd2-8408-2cf7fe1aaab1" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_db17c571-4578-4afa-8c9f-30fa59a69666" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_62b514bd-fe4b-4ab8-97c9-5c4d641aab21" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_db17c571-4578-4afa-8c9f-30fa59a69666" xlink:to="loc_srt_ConsolidationItemsAxis_62b514bd-fe4b-4ab8-97c9-5c4d641aab21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_62b514bd-fe4b-4ab8-97c9-5c4d641aab21_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_62b514bd-fe4b-4ab8-97c9-5c4d641aab21" xlink:to="loc_srt_ConsolidationItemsDomain_62b514bd-fe4b-4ab8-97c9-5c4d641aab21_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_8b001bce-2a95-4ae4-8c9a-5e85ba40408a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_62b514bd-fe4b-4ab8-97c9-5c4d641aab21" xlink:to="loc_srt_ConsolidationItemsDomain_8b001bce-2a95-4ae4-8c9a-5e85ba40408a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_1f5090be-1027-4b15-86bd-30d9b25d7b9d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_8b001bce-2a95-4ae4-8c9a-5e85ba40408a" xlink:to="loc_us-gaap_OperatingSegmentsMember_1f5090be-1027-4b15-86bd-30d9b25d7b9d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_fa3a4dae-9572-428a-a89f-d17942e53005" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_8b001bce-2a95-4ae4-8c9a-5e85ba40408a" xlink:to="loc_us-gaap_CorporateNonSegmentMember_fa3a4dae-9572-428a-a89f-d17942e53005" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_46193bbe-af5d-4404-84c4-16b2a82b91d0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_db17c571-4578-4afa-8c9f-30fa59a69666" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_46193bbe-af5d-4404-84c4-16b2a82b91d0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_46193bbe-af5d-4404-84c4-16b2a82b91d0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_46193bbe-af5d-4404-84c4-16b2a82b91d0" xlink:to="loc_us-gaap_SegmentDomain_46193bbe-af5d-4404-84c4-16b2a82b91d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_e99f6284-f9a1-432b-8f42-df6d5083a8f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_46193bbe-af5d-4404-84c4-16b2a82b91d0" xlink:to="loc_us-gaap_SegmentDomain_e99f6284-f9a1-432b-8f42-df6d5083a8f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_SidingSegmentMember_f5a0e974-fac0-41b5-b577-aaf894761720" xlink:href="lpx-20250930.xsd#lpx_SidingSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_e99f6284-f9a1-432b-8f42-df6d5083a8f7" xlink:to="loc_lpx_SidingSegmentMember_f5a0e974-fac0-41b5-b577-aaf894761720" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_OSBSegmentMember_5d01dfeb-7f60-4dfd-92b2-0b2951177239" xlink:href="lpx-20250930.xsd#lpx_OSBSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_e99f6284-f9a1-432b-8f42-df6d5083a8f7" xlink:to="loc_lpx_OSBSegmentMember_5d01dfeb-7f60-4dfd-92b2-0b2951177239" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_LPSouthAmericaSegmentMember_6293e390-d710-42c8-9b58-7cdee977b9fc" xlink:href="lpx-20250930.xsd#lpx_LPSouthAmericaSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_e99f6284-f9a1-432b-8f42-df6d5083a8f7" xlink:to="loc_lpx_LPSouthAmericaSegmentMember_6293e390-d710-42c8-9b58-7cdee977b9fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_508855b2-a791-46c9-82dd-0ea6056afc5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_fd3d0aeb-a3fc-4cd2-8408-2cf7fe1aaab1" xlink:to="loc_us-gaap_Revenues_508855b2-a791-46c9-82dd-0ea6056afc5b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_338c0b07-7837-4cdf-8693-73d9838e9286" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_fd3d0aeb-a3fc-4cd2-8408-2cf7fe1aaab1" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_338c0b07-7837-4cdf-8693-73d9838e9286" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_044783d7-f2b6-4f3b-a49a-75fd4b4bd714" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_fd3d0aeb-a3fc-4cd2-8408-2cf7fe1aaab1" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_044783d7-f2b6-4f3b-a49a-75fd4b4bd714" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_3fa1c543-836b-422b-91a6-62eb16605ad2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_fd3d0aeb-a3fc-4cd2-8408-2cf7fe1aaab1" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_3fa1c543-836b-422b-91a6-62eb16605ad2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherExpenses_df50dfe6-5da5-41e9-ada4-face804f66df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_fd3d0aeb-a3fc-4cd2-8408-2cf7fe1aaab1" xlink:to="loc_us-gaap_OtherExpenses_df50dfe6-5da5-41e9-ada4-face804f66df" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_AdjustedEBITDA_027c6dfd-72ed-4a43-b97d-b1e240ddafaa" xlink:href="lpx-20250930.xsd#lpx_AdjustedEBITDA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_fd3d0aeb-a3fc-4cd2-8408-2cf7fe1aaab1" xlink:to="loc_lpx_AdjustedEBITDA_027c6dfd-72ed-4a43-b97d-b1e240ddafaa" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_db33b98b-49f1-4fce-81c2-1936ea4248d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_fd3d0aeb-a3fc-4cd2-8408-2cf7fe1aaab1" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_db33b98b-49f1-4fce-81c2-1936ea4248d1" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.lpcorp.com/role/SelectedSegmentDataIdentifiableAssetsbySegmentDetails" xlink:type="simple" xlink:href="lpx-20250930.xsd#SelectedSegmentDataIdentifiableAssetsbySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.lpcorp.com/role/SelectedSegmentDataIdentifiableAssetsbySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_530524ae-8d01-4932-b995-361e21a5f752" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_fd699701-ff07-429b-9faf-aac949aadb7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_530524ae-8d01-4932-b995-361e21a5f752" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_fd699701-ff07-429b-9faf-aac949aadb7b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_49df7e66-2086-4eb5-acd3-bbec044c629d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_fd699701-ff07-429b-9faf-aac949aadb7b" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_49df7e66-2086-4eb5-acd3-bbec044c629d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_49df7e66-2086-4eb5-acd3-bbec044c629d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_49df7e66-2086-4eb5-acd3-bbec044c629d" xlink:to="loc_us-gaap_SegmentDomain_49df7e66-2086-4eb5-acd3-bbec044c629d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_42f878b1-d5d0-47b4-9b92-1a41bedd6ab5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_49df7e66-2086-4eb5-acd3-bbec044c629d" xlink:to="loc_us-gaap_SegmentDomain_42f878b1-d5d0-47b4-9b92-1a41bedd6ab5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_SidingSegmentMember_f74424f0-4230-44a9-b792-4a9ab9cdb133" xlink:href="lpx-20250930.xsd#lpx_SidingSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_42f878b1-d5d0-47b4-9b92-1a41bedd6ab5" xlink:to="loc_lpx_SidingSegmentMember_f74424f0-4230-44a9-b792-4a9ab9cdb133" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_OSBSegmentMember_16551a85-4dc9-4d7c-a998-b195824ee819" xlink:href="lpx-20250930.xsd#lpx_OSBSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_42f878b1-d5d0-47b4-9b92-1a41bedd6ab5" xlink:to="loc_lpx_OSBSegmentMember_16551a85-4dc9-4d7c-a998-b195824ee819" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_lpx_LPSouthAmericaSegmentMember_86029393-344f-4480-b92b-fc60c541c90f" xlink:href="lpx-20250930.xsd#lpx_LPSouthAmericaSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_42f878b1-d5d0-47b4-9b92-1a41bedd6ab5" xlink:to="loc_lpx_LPSouthAmericaSegmentMember_86029393-344f-4480-b92b-fc60c541c90f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllOtherSegmentsMember_59a417af-24fc-414c-ace2-019a5374d842" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllOtherSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_42f878b1-d5d0-47b4-9b92-1a41bedd6ab5" xlink:to="loc_us-gaap_AllOtherSegmentsMember_59a417af-24fc-414c-ace2-019a5374d842" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_46c87f3b-b54e-4eac-8135-a07fcd9af33a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_530524ae-8d01-4932-b995-361e21a5f752" xlink:to="loc_us-gaap_Assets_46c87f3b-b54e-4eac-8135-a07fcd9af33a" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
