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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-02-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000075129</issuerCik>
        <issuerName>OTTER TAIL CORP</issuerName>
        <issuerTradingSymbol>OTTR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001191483</rptOwnerCik>
            <rptOwnerName>ERICKSON JOHN D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>215 S CASCADE ST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>FERGUS FALLS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>56537-2801</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance Rights</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-02-06</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>9300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>9300</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9300</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This is a Performance Share Award and has no conversion or exercise price at this time.</footnote>
        <footnote id="F2">There is no specific &quot;Exercisable Date&quot; on this Performance Share Award.</footnote>
        <footnote id="F3">There is no specific &quot;Expiration Date&quot; on this Performance Share Award.</footnote>
        <footnote id="F4">The grant price of this award was based on fair market value at the time of the grant which was $26.495.</footnote>
        <footnote id="F5">Performance Share Award acquired under the 1999 Stock Incentive Plan.  This award was reaffirmed at the Board of Directors meeting held 2/5/07 - 2/6/07 and is based on performance period of 1/1/2004 - 12/31/2006.  See below for other holdings:
1.  Direct holding of 109.1598 shares of Common Stock held in the Dividend Reinvestment Plan.
2.  Direct holding of 8,038.3615 shares of Common Stock held in the Employee Stock Purchase Plan.
3.  Direct holding of 9,000 shares of Common Stock which is a grant of Restricted Stock.
4.  Direct holding of 40,303 shares of Common Stock which no longer carries the restriction.
5.  Indirect holding of 4,981.6727 shares of Common Stock held by ESOP.
6.  16,000 stock options with expiration date of 2/22/2009.
7.  25,000 stock options with expiration date of 4/9/2010.
8.  75,000 stock options with expiration date of 4/8/2011.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/  John D Erickson by Debra J Lill -POA</signatureName>
        <signatureDate>2007-02-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
