-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 Zdbdkx/uAJnDNwYXBVEk4Q==

<SEC-DOCUMENT>0001459208-09-000002.txt : 20090323
<SEC-HEADER>0001459208-09-000002.hdr.sgml : 20090323
<ACCEPTANCE-DATETIME>20090323142545
ACCESSION NUMBER:		0001459208-09-000002
CONFORMED SUBMISSION TYPE:	D
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		Rule 506
ITEM INFORMATION:		Investment Company Act Section 3(c)
ITEM INFORMATION:		Section 3(c)(1)
FILED AS OF DATE:		20090323
DATE AS OF CHANGE:		20090323
EFFECTIVENESS DATE:		20090323

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Trinity X Side-By-Side Fund, L.P.
		CENTRAL INDEX KEY:			0001459208
		IRS NUMBER:				264432897
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		D
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-128376
		FILM NUMBER:		09698497

	BUSINESS ADDRESS:	
		STREET 1:		3000 SAND HILL ROAD
		STREET 2:		BUILDING 4, SUITE 160
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025
		BUSINESS PHONE:		6508549500

	MAIL ADDRESS:	
		STREET 1:		3000 SAND HILL ROAD
		STREET 2:		BUILDING 4, SUITE 160
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025
</SEC-HEADER>
<DOCUMENT>
<TYPE>D
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<edgarSubmission>

    <schemaVersion>X0301</schemaVersion>

    <submissionType>D</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0001459208</cik>
        <entityName>Trinity X Side-By-Side Fund, L.P.</entityName>
        <issuerAddress>
            <street1>3000 SAND HILL ROAD</street1>
            <street2>BUILDING 4, SUITE 160</street2>
            <city>MENLO PARK</city>
            <stateOrCountry>CA</stateOrCountry>
            <zipCode>94025</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>6508549500</issuerPhoneNumber>
        <issuerPreviousNameList>
            <value>None</value>
        </issuerPreviousNameList>
        <jurisdictionOfInc>DE</jurisdictionOfInc>
        <entityType>Limited Partnership</entityType>
        <yearOfInc>
            <withinFiveYears>true</withinFiveYears>
            <value>2009</value>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>(None)</firstName>
                <middleName></middleName>
                <lastName>Trinity TVL X, LLC</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3000 Sand Hill Road</street1>
                <street2>Building 4, Suite 160</street2>
                <city>Menlo Park</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94025</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>General Partner to Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Lawrence</firstName>
                <middleName>K.</middleName>
                <lastName>Orr</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3000 Sand Hill Road</street1>
                <street2>Building 4, Suite 160</street2>
                <city>Menlo Park</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94025</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Management Member of the General Partner to Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Noel</firstName>
                <middleName>J.</middleName>
                <lastName>Fenton</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3000 Sand Hill Road</street1>
                <street2>Building 4, Suite 160</street2>
                <city>Menlo Park</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94025</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Management Member of the General Partner to Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Augustus</firstName>
                <middleName>O.</middleName>
                <lastName>Tai</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3000 Sand Hill Road</street1>
                <street2>Building 4, Suite 160</street2>
                <city>Menlo Park</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94025</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Management Member of the General Partner to Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Fred</firstName>
                <middleName></middleName>
                <lastName>Wang</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3000 Sand Hill Road</street1>
                <street2>Building 4, Suite 160</street2>
                <city>Menlo Park</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94025</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Management Member of the General Partner to Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Kathleen</firstName>
                <middleName>A.</middleName>
                <lastName>Murphy</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3000 Sand Hill Road</street1>
                <street2>Building 4, Suite 160</street2>
                <city>Menlo Park</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94025</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Management Member of the General Partner to Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Timothy</firstName>
                <middleName>P.</middleName>
                <lastName>McAdam</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3000 Sand Hill Road</street1>
                <street2>Building 4, Suite 160</street2>
                <city>Menlo Park</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94025</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Management Member of the General Partner to Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Patricia</firstName>
                <middleName>E.</middleName>
                <lastName>Nakache</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3000 Sand Hill Road</street1>
                <street2>Building 4, Suite 160</street2>
                <city>Menlo Park</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94025</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Management Member of the General Partner to Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Ajay</firstName>
                <middleName></middleName>
                <lastName>Chopra</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3000 Sand Hill Road</street1>
                <street2>Building 4, Suite 160</street2>
                <city>Menlo Park</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94025</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Management Member of the General Partner to Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>(None)</firstName>
                <middleName></middleName>
                <lastName>TVL Management Corporation</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3000 Sand Hill Road</street1>
                <street2>Building 4, Suite 160</street2>
                <city>Menlo Park</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94025</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Management Member of the General Partner to Issuer</relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Pooled Investment Fund</industryGroupType>
            <investmentFundInfo>
                <investmentFundType>Other Investment Fund</investmentFundType>
                <is40Act>false</is40Act>
            </investmentFundInfo>
        </industryGroup>
        <issuerSize>
            <aggregateNetAssetValueRange>Decline to Disclose</aggregateNetAssetValueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06</item>
            <item>3C</item>
            <item>3C.1</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>false</isAmendment>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2009-03-13</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>false</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isPooledInvestmentFundType>true</isPooledInvestmentFundType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>0</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>1500000</totalOfferingAmount>
            <totalAmountSold>1500000</totalAmountSold>
            <totalRemaining>0</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>7</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
            </findersFees>
            <clarificationOfResponse></clarificationOfResponse>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
            </grossProceedsUsed>
            <clarificationOfResponse></clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>Trinity X Side-By-Side Fund, L.P.</issuerName>
                <signatureName>Kathleen A. Murphy</signatureName>
                <nameOfSigner>Kathleen A. Murphy</nameOfSigner>
                <signatureTitle>Management Member of Trinity TVL X, LLC, General Partner</signatureTitle>
                <signatureDate>2009-03-18</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----