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

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-09-22</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001329860</rptOwnerCik>
            <rptOwnerName>Anderson Joel D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <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>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <officerTitle>Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-09-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>705000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.37</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>87233</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Revocable Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1361684</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3134235</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 2020 Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>229204</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 2025 Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On September 22, 2026, the reporting person contributed 705,000 shares of Petco common stock from the Revocable Trust into the 2020 Trust. In exchange for the shares, the Revocable Trust withdrew an amount equal to $2.37 per share from the 2020 Trust. The contribution of shares to the 2020 Trust resulted in a decrease in the number of shares the reporting person beneficially owns indirectly through the Revocable Trust and a corresponding increase in the number of shares the reporting person beneficially owns indirectly through the 2020 Trust. The reporting person believes that this contribution of shares to the 2020 Trust constitutes a change in the form of beneficial ownership of the shares, exempted by Rule 16a-13 under the Securities Exchange Act of 1934.</footnote>
        <footnote id="F2">On August 4, 2026 and September 15, 2026, respectively, 246,269 and 285,061 shares of Class A common stock of the Issuer were transferred from the reporting person's direct holdings into the Revocable Trust.</footnote>
        <footnote id="F3">Includes 1,347,723 outstanding restricted stock units (&quot;RSUs&quot;) granted under the Petco Health and Wellness Company, Inc. 2021 Equity Incentive 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>2026-09-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
