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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-11-18</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001752836</issuerCik>
        <issuerName>COVETRUS, INC.</issuerName>
        <issuerTradingSymbol>CVET</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001624514</rptOwnerCik>
            <rptOwnerName>CD&amp;R Investment Associates IX, Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O M+C CORPORATE SERVICES LIMITED</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 309 UGLAND HSE, SOUTH CHURCH ST</rptOwnerStreet2>
            <rptOwnerCity>GEORGE TOWN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>KY1-1104</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001766983</rptOwnerCik>
            <rptOwnerName>CD&amp;R VFC Holdings L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O M+C CORPORATE SERVICES LIMITED</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 309 UGLAND HSE, SOUTH CHURCH ST</rptOwnerStreet2>
            <rptOwnerCity>GEORGE TOWN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>KY1-1104</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-11-18</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>8165045</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>33589001</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By affiliate</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-11-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>81540</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>33670541</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By affiliate</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series A Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>11.10</value>
                <footnoteId id="F4"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-11-18</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>90632</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
                <footnoteId id="F7"/>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
                <footnoteId id="F7"/>
                <footnoteId id="F8"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8165045</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By affiliate</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On November 18, 2020, 90,632 shares of 7.5% Series A Preferred Stock (the &quot;Preferred Stock&quot;) of Covetrus, Inc. (the &quot;Issuer&quot;) were converted into 8,165,045 shares of common stock of the Issuer (the &quot;Common Stock&quot;) at the option of the Issuer, pursuant to the terms of the certificate of designations, preferences and right governing the Preferred Stock and following approval by the Issuer's stockholders on November 17, 2020 of the conversion of all outstanding shares of Preferred Stock into shares of Common Stock.</footnote>
        <footnote id="F2">These securities are owned directly by CD&amp;R VFC Holdings, L.P. (&quot;CD&amp;R Stockholder&quot;). CD&amp;R Investment Associates IX, Ltd., as the general partner of CD&amp;R Stockholder, may be deemed to beneficially own the securities held by CD&amp;R Stockholder. CD&amp;R Investment Associates IX, Ltd. expressly disclaims beneficial ownership of the securities held by CD&amp;R Stockholder, except to the extent of its pecuniary interest therein.</footnote>
        <footnote id="F3">On November 18, 2020, in connection with the conversion of all outstanding shares of Preferred Stock by the Issuer, CD&amp;R Stockholder received accrued dividends in respect of the 90,632 shares of Preferred Stock held on the date of conversion in the form of 81,540 shares of Common Stock.</footnote>
        <footnote id="F4">CD&amp;R Stockholder directly owned shares of Preferred Stock of the Issuer, which were convertible into shares of Common Stock at a price per share of $11.10, which was subject to anti-dilution adjustments, including in the event of any stock split, stock dividend, recapitalization of similar event.</footnote>
        <footnote id="F5">The Preferred Stock was convertible at any time at the option of the holder and had no expiration date. Following approval by the Issuer's stockholders on November 17, 2020, the Issuer was able to convert all outstanding shares of Preferred Stock, resulting in the Reporting Persons beneficially owning more than 19.99% of the then-outstanding stockholder voting power of the Issuer.</footnote>
        <footnote id="F6">The Issuer had the right, at its option, to require conversion of all (but not less than all) of the outstanding shares of Preferred Stock to shares of Common Stock if (i) at any time, the Issuer satisfies certain financial metrics or (ii) the volume weighted average price of the Common Stock on any trading day (a) until (but not including) the date that is two years from the issuance date, exceeds 200%, (b) from the date that is two years from the issuance date until (but not including) the date that is two years and six months from the issuance date, exceeds 195%, (c) from the date that is two years and six months from the issuance date until (but not including) the date that is three years from the issuance date, exceeds 190%, (d) from the date that is three years from the issuance date until (but not including) the date that is three years and six months from the issuance date, exceeds 185%, (continued next footnote)</footnote>
        <footnote id="F7">(e) from the date that is three years and six months from the issuance date until (but not including) the date that is four years from the issuance date, exceeds 180%, and (f) at any time thereafter, exceeds 175%, in each case, of the then-effective conversion price for at least 20 out of the 30 trailing trading days. The Preferred Stock accrued dividends at a rate of 7.50% per annum, payable in cash or in additional shares of Preferred Stock.</footnote>
        <footnote id="F8">Holders of Preferred Stock were also entitled to receive certain dividends declared or paid on the Common Stock on an as-converted basis.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>CD&amp;R Investment Associates IX, Ltd., By: Theresa A. Gore, CFO, Treas. and Sec.</signatureName>
        <signatureDate>2020-11-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>CD&amp;R VFC Holdings, L.P., By: CD&amp;R Investment Associates IX, Ltd, general partner; By: /s/ Theresa A. Gore, CFO, Treas. and Sec.</signatureName>
        <signatureDate>2020-11-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
