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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0000902664-10-001560.txt : 20100309
<SEC-HEADER>0000902664-10-001560.hdr.sgml : 20100309
<ACCEPTANCE-DATETIME>20100309121117
ACCESSION NUMBER:		0000902664-10-001560
CONFORMED SUBMISSION TYPE:	D/A
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		Rule 506
ITEM INFORMATION:		Investment Company Act Section 3(c)
ITEM INFORMATION:		Section 3(c)(7)
FILED AS OF DATE:		20100309
DATE AS OF CHANGE:		20100309
EFFECTIVENESS DATE:		20100309

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Convexity Capital Onshore L.P.
		CENTRAL INDEX KEY:			0001459729
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		D/A
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-128654
		FILM NUMBER:		10666031

	BUSINESS ADDRESS:	
		STREET 1:		C/O CONVEXITY CAPITAL MGMT., LP
		STREET 2:		200 CLARENDON STREET, 57TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		(617) 585-8500

	MAIL ADDRESS:	
		STREET 1:		C/O CONVEXITY CAPITAL MGMT., LP
		STREET 2:		200 CLARENDON STREET, 57TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CONVEXITY CAPITAL ONSHORE LP
		DATE OF NAME CHANGE:	20090325
</SEC-HEADER>
<DOCUMENT>
<TYPE>D/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<edgarSubmission>

    <schemaVersion>X0603</schemaVersion>

    <submissionType>D/A</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0001459729</cik>
        <entityName>Convexity Capital Onshore L.P.</entityName>
        <issuerAddress>
            <street1>C/O CONVEXITY CAPITAL MGMT., LP</street1>
            <street2>200 CLARENDON STREET, 57TH FLOOR</street2>
            <city>BOSTON</city>
            <stateOrCountry>MA</stateOrCountry>
            <zipCode>02116</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>(617) 585-8500</issuerPhoneNumber>
        <jurisdictionOfInc>DELAWARE</jurisdictionOfInc>
        <issuerPreviousNameList></issuerPreviousNameList>
        <edgarPreviousNameList>
            <previousName>CONVEXITY CAPITAL ONSHORE LP</previousName>
        </edgarPreviousNameList>
        <entityType>Limited Partnership</entityType>
        <yearOfInc>
            <withinFiveYears>true</withinFiveYears>
            <value>2005</value>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Convexity Capital GP LLC</firstName>
                <lastName>Convexity Capital GP LLC</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Convexity Capital Mgmt., LP</street1>
                <street2>200 Clarendon Street, 57th Floor</street2>
                <city>Boston</city>
                <stateOrCountry>MA</stateOrCountry>
                <zipCode>02116</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>General Partner</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Jack</firstName>
                <middleName>R.</middleName>
                <lastName>Meyer</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Convexity Capital Mgmt., LP</street1>
                <street2>200 Clarendon Street, 57th Floor</street2>
                <city>Boston</city>
                <stateOrCountry>MA</stateOrCountry>
                <zipCode>02116</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Senior Managing Member of the General Partner</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>David</firstName>
                <middleName>R.</middleName>
                <lastName>Mittelman</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Convexity Capital Mgmt., LP</street1>
                <street2>200 Clarendon Street, 57th Floor</street2>
                <city>Boston</city>
                <stateOrCountry>MA</stateOrCountry>
                <zipCode>02116</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Managing Member of the General Partner</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Maurice</firstName>
                <lastName>Samuels</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Convexity Capital Mgmt., LP</street1>
                <street2>200 Clarendon Street, 57th Floor</street2>
                <city>Boston</city>
                <stateOrCountry>MA</stateOrCountry>
                <zipCode>02116</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Managing Member of the General Partner</relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Pooled Investment Fund</industryGroupType>
            <investmentFundInfo>
                <investmentFundType>Hedge Fund</investmentFundType>
                <is40Act>false</is40Act>
            </investmentFundInfo>
        </industryGroup>
        <issuerSize>
            <aggregateNetAssetValueRange>Decline to Disclose</aggregateNetAssetValueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06</item>
            <item>3C</item>
            <item>3C.7</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>true</isAmendment>
                <previousAccessionNumber>9999999997-09-011492</previousAccessionNumber>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2006-02-16</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>true</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isPooledInvestmentFundType>true</isPooledInvestmentFundType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>0</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>Indefinite</totalOfferingAmount>
            <totalAmountSold>50229995</totalAmountSold>
            <totalRemaining>Indefinite</totalRemaining>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>16</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
            </findersFees>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
            </grossProceedsUsed>
            <clarificationOfResponse>All investors work at investment manager.</clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>Convexity Capital Onshore L.P.</issuerName>
                <signatureName>/s/ Jack R. Meyer</signatureName>
                <nameOfSigner>Jack R. Meyer</nameOfSigner>
                <signatureTitle>Senior Managing Member of the General Partner</signatureTitle>
                <signatureDate>2010-03-05</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
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</TEXT>
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</SEC-DOCUMENT>
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