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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-06-18</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001766502</issuerCik>
        <issuerName>Chewy, Inc.</issuerName>
        <issuerTradingSymbol>CHWY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001778154</rptOwnerCik>
            <rptOwnerName>Argos Holdings GP LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>650 MADISON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001777949</rptOwnerCik>
            <rptOwnerName>Buddy Chester Corp.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>19601 N. 27TH AVE.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PHOENIX</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85027</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001777952</rptOwnerCik>
            <rptOwnerName>Buddy Chester Sub Corp.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>19601 N. 27TH AVE.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PHOENIX</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85027</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001518072</rptOwnerCik>
            <rptOwnerName>CIE Management IX Ltd</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>650 MADISON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001709681</rptOwnerCik>
            <rptOwnerName>BC Partners Holdings Ltd</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>650 MADISON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock, par value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2019-06-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>47875000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F3"/>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>47875000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                    <footnoteId id="F9"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock, par value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2019-06-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>47875000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>20.90</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                    <footnoteId id="F9"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock, par value $0.01</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-06-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>47875000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock, par value $0.01</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>47875000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>201680000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F4"/>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                    <footnoteId id="F9"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeHolding>
            <securityTitle>
                <value>Class B Common Stock, par value $0.01</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock, par value $0.01</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>64845000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>64845000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F5"/>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                    <footnoteId id="F9"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Class B Common Stock, par value $0.01</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock, par value $0.01</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>78600000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>78600000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                    <footnoteId id="F9"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each share of Class A common stock of Chewy, Inc. (the &quot;Issuer&quot;) was issued upon conversion of one share of Class B common stock of the Issuer.</footnote>
        <footnote id="F2">Shares of Class B common stock of the Issuer are convertible into shares of Class A common stock of the Issuer on a one-for-one basis at any time at the option of the holder, automatically upon any transfer, with certain exceptions, and upon certain other events as described in the Issuer's registration statement on Form S-1 (File No. 333-231095) relating to the initial public offering of its Class A common stock.</footnote>
        <footnote id="F3">Represents shares of Class A common stock of the Issuer sold by PetSmart Buddy Holdings Corp. to the underwriters in connection with the Issuer's initial public offering at the initial public offering price of $22.00 per share less underwriting discounts and commissions.</footnote>
        <footnote id="F4">Shares of Class B common stock are held by PetSmart Buddy Holdings Corp.</footnote>
        <footnote id="F5">Shares of Class B common stock are held by Buddy Chester Sub Corp.</footnote>
        <footnote id="F6">Shares of Class B common stock are held by Buddy Holdings Corp.</footnote>
        <footnote id="F7">Argos Holdings GP LLC (&quot;GP LLC&quot;) is the general partner of Argos Holdings L.P. (the &quot;Argos&quot;). Argos is the sole common equity holder of Citrus Intermediate Holdings L.P. (&quot;Citrus&quot;). GP LLC is the general partner of Citrus. Citrus is the sole stockholder of Argos Intermediate Holdco I Inc. (&quot;Holdco I&quot;). Holdco I is the sole stockholder of Argos Intermediate Holdco II Inc. (&quot;Holdco II&quot;). Holdco II is the sole stockholder of Argos Intermediate Holdco III Inc. (&quot;Holdco III&quot;). Holdco III is the sole stockholder of Buddy Holdings Corp. and Argos Holdings Inc. (&quot;Holdings&quot;). Holdings is the sole stockholder of PetSmart, Inc. (&quot;PetSmart&quot;). PetSmart is the sole stockholder of PetSmart Buddy Holdings Corp. and Buddy Chester Corp. (&quot;Chester&quot;). Chester is the sole stockholder of Buddy Chester Sub Corp.</footnote>
        <footnote id="F8">(continued from footnote 7) CIE Management IX Limited controls a majority of the equity interests of GP LLC and has the power to appoint members to the board of directors of GP LLC who may exercise majority voting power at meetings of the board of directors of GP LLC. BC Partners Holdings Limited is the controlling shareholder of CIE Management IX Limited.</footnote>
        <footnote id="F9">Each Reporting Person may be deemed to be the beneficial owner of all or a portion of the securities reported herein. The filing of this statement shall not be deemed to be an admission that, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;), or otherwise, the Reporting Persons are the beneficial owners of any securities reported herein. The Reporting Persons disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein. On the basis of the relationship between each of Mr. Raymond Svider, Mr. Fahim Ahmed, Mr. Michael Chang and other directors of the Issuer designed or nominated by the Reporting Persons, the Reporting Persons may be directors of the Issuer by deputization for the purposes of Section 16 of the Exchange Act.</footnote>
    </footnotes>

    <remarks>Because no more than 10 reporting persons can file any one Form 4 through the Securities and Exchange Commission's EDGAR system, Argos Holdings L.P., Citrus Intermediate Holdings L.P., Argos Intermediate Holdco I Inc., Argos Intermediate Holdco II Inc., Argos Intermediate Holdco III Inc., Buddy Holdings Corp., Argos Holdings Inc., PetSmart, Inc. and PetSmart Buddy Holdings Corp. have filed a separate Form 4.</remarks>

    <ownerSignature>
        <signatureName>/s/ Susan Helfrick, as Attorney-in-Fact for Reporting Person</signatureName>
        <signatureDate>2019-06-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
