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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-03-08</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001611647</issuerCik>
        <issuerName>Freshpet, Inc.</issuerName>
        <issuerTradingSymbol>FRPT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001268107</rptOwnerCik>
            <rptOwnerName>MIDOCEAN ASSOCIATES SPC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MIDOCEAN PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>320 PARK AVENUE, SUITE 1600</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>0001268105</rptOwnerCik>
            <rptOwnerName>VIRTUE J EDWARD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MIDOCEAN PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>320 PARK AVENUE, SUITE 1600</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>0001268106</rptOwnerCik>
            <rptOwnerName>ULTRAMAR CAPITAL LTD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MIDOCEAN PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>320 PARK AVENUE, SUITE 1600</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>0001372837</rptOwnerCik>
            <rptOwnerName>MIDOCEAN PARTNERS III L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MIDOCEAN PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>320 PARK AVENUE, SUITE 1600</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>0001372838</rptOwnerCik>
            <rptOwnerName>MIDOCEAN PARTNERS III-A L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MIDOCEAN PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>320 PARK AVENUE, SUITE 1600</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>0001372839</rptOwnerCik>
            <rptOwnerName>MIDOCEAN PARTNERS III-D L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MIDOCEAN PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>320 PARK AVENUE, SUITE 1600</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>0001628540</rptOwnerCik>
            <rptOwnerName>MidOcean US Advisor, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MIDOCEAN PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>320 PARK AVENUE, SUITE 1600</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>Common Stock</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </securityTitle>
            <transactionDate>
                <value>2019-03-08</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4000000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>38.57</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3294653</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">2,030,000 shares of Common Stock are held by MidOcean Partners III, L.P. 1,079,226 shares of Common Stock are held by MidOcean Partners III-A, L.P. and 173,094 shares of Common Stock are held by MidOcean III-D, L.P. (collectively, the &quot;MidOcean Entities&quot;). MidOcean Associates, SPC, by and on behalf of its Segregated Portfolio, MidOcean Partners Segregated Portfolio III (&quot;Associates&quot;), is the General Partner of each of the MidOcean Entities. MidOcean US Advisor, L.P. (&quot;US Advisor&quot;) provides investment advisory services to each of the MidOcean Entities and Associates, and has received 12,333 shares of restricted Common Stock that were awarded to US Advisor under the Issuer's 2014 Omnibus Incentive Plan for director services provided by Jonathan Marlow.</footnote>
        <footnote id="F2">(Continued from footnote 1) 10,053 of the shares of restricted Common Stock held by US Advisor have vested, with the remaining 2,280 shares to vest on the first anniversary of the grant date, subject to the continued service of Jonathan Marlow (or another appointee of MidOcean Partners) on the Board of Directors of the Issuer at such date. J. Edward Virtue indirectly controls the shares of common stock held by the MidOcean Entities and the Common Stock held by US Advisor. Accordingly, Associates, US Advisor and Mr. Virtue may be deemed to have beneficial ownership of the shares of Common Stock held by the MidOcean Entities and Mr. Virtue may be deemed to have beneficial ownership of the shares of Common Stock held by US Advisor. Each of Associates, US Advisor and Mr. Virtue disclaim beneficial ownership of the shares owned of record by any other person or entity except to the extent of their pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>MIDOCEAN ASSOCIATES, SPC, by and on behalf of its Segregated Portfolio, MidOcean Partners Segregated Portfolio III, /s/ J. Edward Virtue, By: J. Edward Virtue, Title: Managing Director</signatureName>
        <signatureDate>2019-03-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>MIDOCEAN PARTNERS III, L.P., By: MidOcean Associates, SPC, by and on behalf of its Segregated Portfolio, MidOcean Partners Segregated Portfolio III, its general partner, /s/ J. Edward Virtue, By: J. Edward Virtue, Title: Managing Director</signatureName>
        <signatureDate>2019-03-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>MIDOCEAN PARTNERS III-A, L.P., By: MidOcean Associates, SPC, by and on behalf of its Segregated Portfolio, MidOcean Partners Segregated Portfolio III, its general partner, /s/ J. Edward Virtue, By: J. Edward Virtue, Title: Managing Director</signatureName>
        <signatureDate>2019-03-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>MIDOCEAN PARTNERS III-D, L.P., By: MidOcean Associates, SPC, by and on behalf of its Segregated Portfolio, MidOcean Partners Segregated Portfolio III, its general partner, /s/ J. Edward Virtue, By: J. Edward Virtue, Title: Managing Director</signatureName>
        <signatureDate>2019-03-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>MIDOCEAN US ADVISOR, L.P., /s/ J. Edward Virtue, By: J. Edward Virtue, Title: Chief Executive Officer</signatureName>
        <signatureDate>2019-03-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>ULTRAMAR CAPITAL LTD., /s/ J. Edward Virtue, By: J. Edward Virtue, Title: Chief Executive Officer</signatureName>
        <signatureDate>2019-03-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>J. EDWARD VIRTUE, /s/ J. Edward Virtue</signatureName>
        <signatureDate>2019-03-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
