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    ACCESSION NUMBER:		0001999371-24-001458
    CONFORMED SUBMISSION TYPE:	N-CSR
    PUBLIC DOCUMENT COUNT:		27
    CONFORMED PERIOD OF REPORT:	20231130
    FILED AS OF DATE:		20240202
    DATE AS OF CHANGE:		20240202
    EFFECTIVENESS DATE:		20240202

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			Flaherty & Crumrine PREFERRED & INCOME OPPORTUNITY FUND INC
    		CENTRAL INDEX KEY:			0000882071
    		ORGANIZATION NAME:
    		IRS NUMBER:				954355600
    		STATE OF INCORPORATION:			MD
    		FISCAL YEAR END:			1130

    	FILING VALUES:
    		FORM TYPE:		N-CSR
    		SEC ACT:		1940 Act
    		SEC FILE NUMBER:	811-06495
    		FILM NUMBER:		24590453

    	BUSINESS ADDRESS:
    		STREET 1:		301 E COLORADO BLVD STE 720
    		STREET 2:		C/O FLAHERTY & CRUMRINE INC
    		CITY:			PASADENA
    		STATE:			CA
    		ZIP:			91101
    		BUSINESS PHONE:		(626) 795-7300

    	MAIL ADDRESS:
    		STREET 1:		301 COLORADO BLVD STE 800
    		STREET 2:		C/O FLAHERTY & CRUMRINE INC
    		CITY:			PASADENA
    		STATE:			CA
    		ZIP:			91101

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	Flaherty & Crumrine PREFERRED INCOME OPPORTUNITY FUND INC
    		DATE OF NAME CHANGE:	20050708

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	PREFERRED INCOME OPPORTUNITY FUND INC
    		DATE OF NAME CHANGE:	19920929
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    <TYPE>N-CSR
    <SEQUENCE>1
    <FILENAME>pfo-ncsr_113023.htm
    <DESCRIPTION>CERTIFIED ANNUAL SHAREHOLDER REPORT
    <TEXT>
    Document 1 - file: pfo-ncsr_113023.htm

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    <TYPE>EX-99.CODE ETH
    <SEQUENCE>2
    <FILENAME>ex99-coe.htm
    <DESCRIPTION>CODE OF ETHICS
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    <DESCRIPTION>SECTION 302 CERTIFICATIONS
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    <FILENAME>ex99-c.htm
    <DESCRIPTION>CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
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    <TYPE>EXCEL
    <SEQUENCE>20
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    <TEXT>
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    <SEQUENCE>21
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    <TEXT>
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    <TYPE>XML
    <SEQUENCE>22
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    <TEXT>
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    <TYPE>XML
    <SEQUENCE>24
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    <TEXT>
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    <TYPE>JSON
    <SEQUENCE>26
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    <TEXT>
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    <TEXT>
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