<SEC-DOCUMENT>0001466593-23-000039.txt : 20230209
<SEC-HEADER>0001466593-23-000039.hdr.sgml : 20230209
<ACCEPTANCE-DATETIME>20230209163105
ACCESSION NUMBER:		0001466593-23-000039
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20230207
FILED AS OF DATE:		20230209
DATE AS OF CHANGE:		20230209

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MACFARLANE CHARLES S
		CENTRAL INDEX KEY:			0001278053

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-53713
		FILM NUMBER:		23606704

	MAIL ADDRESS:	
		STREET 1:		215 S CASCADE ST
		CITY:			FERGUS FALLS
		STATE:			MN
		ZIP:			56537-2801

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Otter Tail Corp
		CENTRAL INDEX KEY:			0001466593
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC SERVICES [4911]
		IRS NUMBER:				270383995
		STATE OF INCORPORATION:			MN
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		215 S CASCADE ST
		STREET 2:		PO BOX 496
		CITY:			FERGUS FALLS
		STATE:			MN
		ZIP:			56538-0496
		BUSINESS PHONE:		866-410-8780

	MAIL ADDRESS:	
		STREET 1:		215 S CASCADE ST
		STREET 2:		PO BOX 496
		CITY:			FERGUS FALLS
		STATE:			MN
		ZIP:			56538-0496

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Otter Tail Holding Co
		DATE OF NAME CHANGE:	20090618
</SEC-HEADER>
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<TYPE>4
<SEQUENCE>1
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<DESCRIPTION>FORM 4
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        <issuerName>Otter Tail Corp</issuerName>
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            <rptOwnerName>MACFARLANE CHARLES S</rptOwnerName>
        </reportingOwnerId>
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            <rptOwnerStreet1>215 SOUTH CASCADE STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>FERGUS FALLS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>56537</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
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                <value>Common Stock</value>
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                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
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                <natureOfOwnership>
                    <value>by Grantor Retained Annuity Trust</value>
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                <natureOfOwnership>
                    <value>by Spousal Lifetime Access Trust</value>
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                <value>Common Stock</value>
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                <value>Restricted Stock Units</value>
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                <value>2022-02-06</value>
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                <footnoteId id="F5"/>
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                <underlyingSecurityTitle>
                    <value>Common Stock</value>
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                <footnoteId id="F5"/>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
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                    <value>6525.0</value>
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                <sharesOwnedFollowingTransaction>
                    <value>6525</value>
                </sharesOwnedFollowingTransaction>
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    <footnotes>
        <footnote id="F1">Represents shares received upon the vesting of certain performance criteria in connection with a Performance Share Award (granted in 2020).</footnote>
        <footnote id="F2">These shares were withheld by the Corporation to pay taxes due upon vesting of this award, exempt pursuant to Rule 16b-3(e).</footnote>
        <footnote id="F3">Total direct holdings include shares acquired through the Dividend Reinvestment Plan, the Employee Stock Purchase Plan and shares acquired pursuant to Stock Options, Restricted Stock Awards, Restricted Stock Units and Performance Share Awards.</footnote>
        <footnote id="F4">Each restricted stock unit represents a contingent right to receive one share of Otter Tail Corporation stock.</footnote>
        <footnote id="F5">The restricted stock units vest in four equal annual installments beginning the date shown above.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Charles S. MacFarlane by Mitchell L. Bossert, Attorney-in-Fact</signatureName>
        <signatureDate>2023-02-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
