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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-09-09</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>2020-09-09</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>14357478</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25423956</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="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-09-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>159368</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
                <footnoteId id="F7"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
                <footnoteId id="F7"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>14357478</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>90632</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By affiliate</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On September 9, 2020, 159,368 shares of 7.5% Series A Preferred Stock (the &quot;Preferred Stock&quot;) of Covetrus, Inc. (the &quot;Issuer&quot;) were converted into 14,357,477 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.</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 shares of Common Stock and Preferred Stock held by CD&amp;R Stockholder. CD&amp;R Investment Associates IX, Ltd. expressly disclaims beneficial ownership of the shares of Common Stock and Preferred Stock held by CD&amp;R Stockholder, except to the extent of its pecuniary interest therein.</footnote>
        <footnote id="F3">CD&amp;R Stockholder directly owns 90,632 shares of Preferred Stock of the Issuer, which are convertible into shares of Common Stock at a price per share of $11.10, which is subject to anti-dilution adjustments, including in the event of any stock split, stock dividend, recapitalization of similar event.</footnote>
        <footnote id="F4">The Series A Preferred Stock is convertible at any time at the option of the holder and has no expiration date. Unless certain stockholder approval is obtained, no holder may convert any share of Series A Preferred Stock if the conversion of such share would result in such holder beneficially owning more than 19.99% of the then-outstanding stockholder voting power of the Issuer.</footnote>
        <footnote id="F5">The Issuer may, at its option, require conversion of all (but not less than all) of the outstanding shares of Series A Preferred Stock to shares of the 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="F6">(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 Series A Preferred Stock accrues dividends at a rate of 7.50% per annum, payable in cash or in additional shares of Series A Preferred Stock.</footnote>
        <footnote id="F7">Holders of Series A Preferred Stock are 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>2020-09-11</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>2020-09-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
