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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000202058</issuerCik>
        <issuerName>L3HARRIS TECHNOLOGIES, INC. /DE/</issuerName>
        <issuerTradingSymbol>LHX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001696061</rptOwnerCik>
            <rptOwnerName>Gautier Todd W.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O L3HARRIS TECHNOLOGIES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1025 WEST NASA BOULEVARD</rptOwnerStreet2>
            <rptOwnerCity>MELBOURNE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>32919</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, Aviation Systems</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, Par Value $1.00</value>
            </securityTitle>
            <transactionDate>
                <value>2019-12-31</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>153</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>197.87</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17029.13</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Shares withheld by Issuer to pay tax liability incident to vesting on 12/31/2019 of 565 restricted stock units denominated in shares of Issuer's common stock (previously reported as acquired by reporting person on June 29, 2019 upon completion of the merger (the &quot;Merger&quot;) of Leopard Merger Sub Inc., a subsidiary of Issuer, with and into L3 Technologies, Inc. (&quot;L3&quot;) pursuant to the Agreement and Plan of Merger, dated as of October 12, 2018, and which were converted from L3 performance stock units in connection with the Merger, with vesting on last day of original performance period applicable to such L3 performance stock units, subject to reporting person's continued employment) and receipt of shares in settlement thereof.</footnote>
        <footnote id="F2">Includes 1.13 shares acquired through Issuer's retirement plan on 9/18/2019.</footnote>
    </footnotes>

    <remarks>Exhibit List:

Exhibit 24 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>By: /s/ Robert A. Johnson Jr., Attorney-in-Fact For:

Todd W. Gautier</signatureName>
        <signatureDate>2020-01-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
