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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-03-04</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>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2025-03-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>223578</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>604289</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option  (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.46</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-03-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>172956</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2035-03-04</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>172956</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>172956</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-03-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>142488</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>142488</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>142488</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents 223,578 restricted stock units (&quot;RSUs&quot;) granted under the Petco Health and Wellness Company, Inc. 2021 Equity Incentive Plan (as amended, the &quot;2021 Plan&quot;). Each RSU represents the right to receive one share of Class A common stock of the Issuer. The RSUs will vest in the following installments: (i) 34% on the first anniversary of 3/4/2025 (the &quot;Grant Date&quot;); (ii) 16.5% on the date that is 18 months following the Grant Date; (iii) 16.5% on the second anniversary of the Grant Date; (iv) 16.5% on the date that is 30 months following the Grant Date; and (v) 16.5% on the third anniversary of the Grant Date.</footnote>
        <footnote id="F2">Represents options to purchase Class A Common Stock granted under the 2021 Plan. The options will vest as follows: (i) 34% on the first anniversary of the Grant Date; (ii) 16.5% on the date that is 18 months following the Grant Date; (iii) 16.5% on the second anniversary of the Grant Date; (iv) 16.5% on the date that is 30 months following the Grant Date; and (v) 16.5% on the third anniversary of the Grant Date.</footnote>
        <footnote id="F3">Represents the target number of performance stock units (&quot;PSUs&quot;) granted under the 2021 Plan. The PSUs represent the right to receive shares of Class A common stock of the Issuer in an amount from 0% to 200% of the target number of PSUs granted. The actual number of PSUs earned will be determined following a performance period ending January 29, 2028, based on the Issuer's total shareholder return during the performance period and subject to continued employment through the vesting date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Giovanni Insana, as Attorney-in-Fact</signatureName>
        <signatureDate>2025-03-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
