<SUBMISSION>
<ACCESSION-NUMBER>0001209191-04-004168
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20040120
<FILING-DATE>20040122
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>SIMLER YARON
<CIK>0001216450
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-25826
<FILM-NUMBER>04538018
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>HARMONIC INC
<STREET2>549 BALTIC WAY
<CITY>SUNNYVALE
<STATE>CA
<ZIP>94089
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>HARMONIC INC
<CIK>0000851310
<ASSIGNED-SIC>3663
<IRS-NUMBER>770201147
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>549 BALTIC WAY
<CITY>SUNNYVALE
<STATE>CA
<ZIP>94089
<PHONE>4085422500
</BUSINESS-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>HARMONIC LIGHTWAVES INC
<DATE-CHANGED>19950404
</FORMER-COMPANY>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?><ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2004-01-20</periodOfReport><notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000851310</issuerCik>
        <issuerName>HARMONIC INC</issuerName>
        <issuerTradingSymbol>HLIT</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001216450</rptOwnerCik>
            <rptOwnerName>SIMLER YARON</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>549 BALTIC WAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SUNNYVALE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94089</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>President, CSD</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>6718.0000</value><footnoteId id="F1" /></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Right to Buy (options)</value></securityTitle><conversionOrExercisePrice><value>9.2900</value></conversionOrExercisePrice><transactionDate><value>2004-01-20</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>40000.0000</value></transactionShares><transactionPricePerShare><value>9.2900</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2005-01-20</value><footnoteId id="F2" /></exerciseDate><expirationDate><value>2014-01-20</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>40000.0000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>40000.0000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">This total includes 1,669 shares acquired in the Harmonic Employee Stock Purchase Plan on January 2, 2004.</footnote><footnote id="F2">Twenty-five percent of the Shares subject to the Option vested twelve months after the Vesting Commencement Date, and 1/48 of the Shares subject to the Option vested each month thereafter.</footnote></footnotes><remarks></remarks><ownerSignature><signatureName>/s/Laura Donovan
By: Laura Donovan, Attorney-In-Fact</signatureName><signatureDate>2004-01-22</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
