<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-03-04</periodOfReport>

    <issuer>
        <issuerCik>0001826470</issuerCik>
        <issuerName>Petco Health &amp; Wellness Company, Inc.</issuerName>
        <issuerTradingSymbol>WOOF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001559039</rptOwnerCik>
            <rptOwnerName>Venezia Patrick J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PETCO HEALTH AND WELLNESS COMPANY,</rptOwnerStreet1>
            <rptOwnerStreet2>INC., 10850 VIA FRONTERA</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92127</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>Chief Revenue Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-03-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>32792</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.65</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>442056</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The transaction reported reflects the withholding of restricted stock units (&quot;RSUs&quot;) in satisfaction of the Reporting Person's tax liability. The RSUs were granted to the Reporting Person on March 4, 2025 pursuant to the Petco Health
and Wellness Company, Inc. 2021 Equity Incentive Plan (as amended, the &quot;2021 Plan&quot;), and a portion vested on March 4, 2026.</footnote>
        <footnote id="F2">Includes 398,832 outstanding RSUs granted under the 2021 Plan. Each RSU represents the right to receive one share of Class A common stock of the Issuer.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Giovanni Insana, as Attorney-in-Fact</signatureName>
        <signatureDate>2026-03-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
