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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-11-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001664998</issuerCik>
        <issuerName>KnowBe4, Inc.</issuerName>
        <issuerTradingSymbol>KNBE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001655249</rptOwnerCik>
            <rptOwnerName>Elephant Partners GP I, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>8 NEWBURY STREET</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001847020</rptOwnerCik>
            <rptOwnerName>Elephant Partners GP II, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>8 NEWBURY STREET</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001655267</rptOwnerCik>
            <rptOwnerName>Elephant Partners I, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>8 NEWBURY STREET</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001733916</rptOwnerCik>
            <rptOwnerName>Elephant Partners II, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>8 NEWBURY STREET</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001733917</rptOwnerCik>
            <rptOwnerName>Elephant Partners II-B, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>8 NEWBURY STREET</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001779116</rptOwnerCik>
            <rptOwnerName>Elephant Partners 2019 SPV-A, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>8 NEWBURY STREET</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001858296</rptOwnerCik>
            <rptOwnerName>Hunt Andrew</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ELEPHANT PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>8 NEWBURY STREET, 6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</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</value>
            </securityTitle>
            <transactionDate>
                <value>2021-11-15</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>4966691</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4966691</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-11-15</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4966691</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>24.72</value>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-11-15</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>4966691</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4966691</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>37069823</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each share of the Issuer's Class B Common Stock, par value $0.00001 per share (the &quot;Class B Common Stock&quot;) is convertible at any time at the option of the holder into one share of the Issuer's Class A Common Stock, par value $0.00001 per share (the &quot;Class A Common Stock&quot;). Additionally, each share of Class B Common Stock will, subject to certain conditions and exceptions, convert automatically into one share of Class A Common Stock upon any transfer.</footnote>
        <footnote id="F2">Consists of (i) 3,540,723 shares held by Elephant Partners I, L.P., (ii) 310,367 shares held by Elephant Partners II, L.P. for itself and as nominee for Elephant Partners II-B, L.P., and (iii) 1,115,601 shares held by Elephant Partners 2019 SPV-A, L.P. (collectively, the &quot;Elephant Entities&quot;). Elephant Partners GP I, LLC is the general partner of each of Elephant Partners I, L.P. and Elephant Partners 2019 SPV-A, L.P., and Elephant Partners GP II, LLC is the general partner of each of Elephant Partners II, L.P. and Elephant Partners II-B, L.P. Jeremiah Daly and Andrew Hunt are the managing members of each of Elephant Partners GP I, LLC and Elephant Partners GP II, LLC and may be deemed to have voting and dispositive power over the shares held by each of the Elephant Entities. Mr. Daly is a director of the Issuer and files separate Section 16 reports.</footnote>
        <footnote id="F3">Each of Elephant Partners GP I, LLC, Elephant Partners GP II, LLC, Jeremiah Daly and Andrew Hunt disclaims beneficial ownership of the securities reported herein, except to the extent of such Reporting Person's pecuniary interest therein, and 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 or otherwise, any of them is the beneficial owner of any securities reported herein.</footnote>
        <footnote id="F4">Pursuant to an underwriting agreement and in connection with a registered public offering of shares of the Issuer's Class A Common Stock, pursuant to a final prospectus dated November 10, 2021, which offering was consummated on November 15, 2021, the Elephant Entities collectively sold 4,966,691 shares of Class A Common Stock, at a price per share of $24.72 (after underwriting discounts and commissions). Each of the Elephant Entities was a selling stockholder in the registered public offering.</footnote>
        <footnote id="F5">Consists of (i) 26,426,861 shares held by Elephant Partners I, L.P., (ii) 2,316,470 shares held by Elephant Partners II, L.P. for itself and as nominee for Elephant Partners II-B, L.P., and (ii) 8,326,492 shares held by Elephant Partners 2019 SPV-A, L.P. Elephant Partners GP I, LLC is the general partner of each of Elephant Partners I, L.P. and Elephant Partners 2019 SPV-A, L.P., and Elephant Partners GP II, LLC is the general partner of each of Elephant Partners II, L.P. and Elephant Partners II-B, L.P. Jeremiah Daly and Andrew Hunt are the managing members of each of Elephant Partners GP I, LLC and Elephant Partners GP II, LLC and may be deemed to have voting and dispositive power over the shares held by each of the Elephant Entities. Mr. Daly is a director of the Issuer and files separate Section 16 reports.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Patrick Cammarata, Authorized Officer of Elephant Partners GP I, LLC</signatureName>
        <signatureDate>2021-11-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Patrick Cammarata, Authorized Officer of Elephant Partners GP II, LLC</signatureName>
        <signatureDate>2021-11-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Patrick Cammarata, Authorized Officer of Elephant Partners GP I, LLC, the general partner of Elephant Partners I, L.P.</signatureName>
        <signatureDate>2021-11-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Patrick Cammarata, Authorized Officer of Elephant Partners GP II, LLC, the general partner of Elephant Partners II, L.P.</signatureName>
        <signatureDate>2021-11-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Patrick Cammarata, Authorized Officer of Elephant Partners GP II, LLC, the general partner of Elephant Partners II-B, L.P.</signatureName>
        <signatureDate>2021-11-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Patrick Cammarata, Authorized Officer of Elephant Partners GP I, LLC, the general partner of Elephant Partners 2019 SPV-A, L.P.</signatureName>
        <signatureDate>2021-11-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Patrick Cammarata, Attorney-in-Fact for Andrew Hunt</signatureName>
        <signatureDate>2021-11-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
