-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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MIC-Info: RSA-MD5,RSA,
 EhNV8Z8tm10P9yumLern9Kjx0Wqdsn35Difge+PPNsoxP5SFB6ml4ZBiAWdIOMdY
 qhfVVNPGl2YNJinfSzV+6A==

<SEC-DOCUMENT>0001140361-10-043329.txt : 20101103
<SEC-HEADER>0001140361-10-043329.hdr.sgml : 20101103
<ACCEPTANCE-DATETIME>20101103131510
ACCESSION NUMBER:		0001140361-10-043329
CONFORMED SUBMISSION TYPE:	D/A
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		Rule 506
ITEM INFORMATION:		Section 3(c)(7)
FILED AS OF DATE:		20101103
DATE AS OF CHANGE:		20101103
EFFECTIVENESS DATE:		20101103

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HORIZON PORTFOLIO I LTD
		CENTRAL INDEX KEY:			0001449223
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			E9
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		D/A
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-124128
		FILM NUMBER:		101160740

	BUSINESS ADDRESS:	
		STREET 1:		UGLAND HOUSE, PO BOX 309
		CITY:			GEORGE TOWN, GRAND CAYMAN
		STATE:			E9
		ZIP:			KY1-1104
		BUSINESS PHONE:		00 353 1 655 8209

	MAIL ADDRESS:	
		STREET 1:		UGLAND HOUSE, PO BOX 309
		CITY:			GEORGE TOWN, GRAND CAYMAN
		STATE:			E9
		ZIP:			KY1-1104
</SEC-HEADER>
<DOCUMENT>
<TYPE>D/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<edgarSubmission>

    <schemaVersion>X0704</schemaVersion>

    <submissionType>D/A</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0001449223</cik>
        <entityName>HORIZON PORTFOLIO I LTD</entityName>
        <issuerAddress>
            <street1>Ugland House, PO Box 309</street1>
            <city>GEORGE TOWN, GRAND CAYMAN</city>
            <stateOrCountry>E9</stateOrCountry>
            <stateOrCountryDescription>CAYMAN ISLANDS</stateOrCountryDescription>
            <zipCode>KY1-1104</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>00 353 1 655 8209</issuerPhoneNumber>
        <jurisdictionOfInc>CAYMAN ISLANDS</jurisdictionOfInc>
        <issuerPreviousNameList>
            <value>None</value>
        </issuerPreviousNameList>
        <edgarPreviousNameList>
            <value>None</value>
        </edgarPreviousNameList>
        <entityType>Corporation</entityType>
        <yearOfInc>
            <overFiveYears>true</overFiveYears>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Sherif</firstName>
                <lastName>Nadar</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Ugland House, PO Box 309</street1>
                <city>George Town, Grand Cayman</city>
                <stateOrCountry>E9</stateOrCountry>
                <stateOrCountryDescription>CAYMAN ISLANDS</stateOrCountryDescription>
                <zipCode>KY1-1104</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>David</firstName>
                <lastName>Sargison</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Ugland House, PO Box 309</street1>
                <city>George Town, Grand Cayman</city>
                <stateOrCountry>E9</stateOrCountry>
                <stateOrCountryDescription>CAYMAN ISLANDS</stateOrCountryDescription>
                <zipCode>KY1-1104</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Douglas</firstName>
                <lastName>Caldor</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Ugland House, PO Box 309</street1>
                <city>George Town, Grand Cayman</city>
                <stateOrCountry>E9</stateOrCountry>
                <stateOrCountryDescription>CAYMAN ISLANDS</stateOrCountryDescription>
                <zipCode>KY1-1104</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Hurley</firstName>
                <lastName>Doddy</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Ugland House, PO Box 309</street1>
                <city>George Town, Grand Cayman</city>
                <stateOrCountry>E9</stateOrCountry>
                <stateOrCountryDescription>CAYMAN ISLANDS</stateOrCountryDescription>
                <zipCode>KY1-1104</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
        </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.7</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>true</isAmendment>
                <previousAccessionNumber>0000902664-09-003770</previousAccessionNumber>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2008-09-01</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>true</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isEquityType>true</isEquityType>
            <isPooledInvestmentFundType>true</isPooledInvestmentFundType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>50000</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>Indefinite</totalOfferingAmount>
            <totalAmountSold>147117543</totalAmountSold>
            <totalRemaining>Indefinite</totalRemaining>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>11</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
            </findersFees>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
            </grossProceedsUsed>
            <clarificationOfResponse>The fund charges a management fee that is described in the fund?s governing documents.</clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>HORIZON PORTFOLIO I LTD</issuerName>
                <signatureName>/s/ Hurley Doddy</signatureName>
                <nameOfSigner>Hurley Doddy</nameOfSigner>
                <signatureTitle>Director</signatureTitle>
                <signatureDate>2010-11-01</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----