Nuveen Floating Rate Income Opportunity Fund

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

FORM N-Q


QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number         811-21579         

        Nuveen Floating Rate Income Opportunity Fund         
(Exact name of registrant as specified in charter)


        333 West Wacker Drive, Chicago, Illinois, 60606         
Address of principal executive offices) (Zip code)


Jessica R. Droeger—Vice President and Secretary
        333 West Wacker Drive, Chicago, Illinois, 60606         
(Name and address of agent for service)

Registrant's telephone number, including area code:         312-917-7700        

Date of fiscal year end:            07/31          

Date of reporting period:          10/31/04         

Form N-Q is to be used by management investment companies, other than small business investment companies registered on Form N-5 (§§ 239.24 and 274.5 of this chapter), to file reports with the Commission, not later than 60 days after the close of the first and third fiscal quarters, pursuant to rule 30b1-5 under the Investment Company Act of 1940 (17 CFR 270.30b1-5). The Commission may use the information provided on Form N-Q in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-Q, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-Q unless the Form displays a currently valid Office of Management and Budget (“OMB”) control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to the Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Schedule of Investments

Portfolio of Investments (Unaudited)
Nuveen Floating Rate Income Opportunity Fund (JRO)
October 31, 2004

Ratings*

Principal

Stated

Market

Amount (000)

Description(1)

Moody's

S&P

Maturity**

Value

VARIABLE RATE SENIOR LOAN INTERESTS(2) - 89.0% (49.4% of total assets)

Airlines - 1.5% (0.8% of total assets)
$

6,000

United Air Lines, Inc., DIP Term Loan (Tranche B)

NR

NR

06/30/05

$    6,067,500
 

Auto Components - 1.2% (0.7% of total assets)

5,230

Federal-Mogul Corporation, Revolver (a)

NR

NR

02/05/05

4,839,611
 

Beverages - 1.5% (0.8% of total assets)

5,726

Dr. Pepper/Seven UP Bottling Group, Inc., Term Loan B

B1

NR

12/19/10

5,808,808
 

Building Products - 2.5% (1.4% of total assets)

10,000

Nortek, Inc., Term Loan B

B1

B+

08/27/11

10,158,335
 

Chemicals - 5.6% (3.1% of total assets)

6,000

Huntsman International LLC, Term Loan

NR

B

03/31/10

6,093,126
 

6,000

Huntsman International LLC, Term Loan B

B1

B

12/31/10

6,106,500
 

10,000

Rockwood Specialties Group, Inc., Term Loan B (c)

B1

B+

07/30/12

10,113,280
 

22,312,906
 

Commercial Services & Supplies - 4.2% (2.3% of total assets)

5,762

Allied Waste North America, Inc., Term Loan B (c)

B1

BB

01/15/10

5,828,758
 

8,808

Allied Waste North America, Inc., Term Loan C (c)

B1

BB

01/15/10

8,903,297
 

1,995

National Equipment Services, Inc., Term Loan

B3

B

08/17/10

1,997,491
 

16,729,546
 

Construction & Engineering - 0.6% (0.3% of total assets)

1,421

Anthony Crane Rental, L.P., Revolver (a)

NR

NR

07/22/04

1,144,285
 

1,569

Anthony Crane Rental, L.P., Term Loan (a)

NR

NR

07/23/04

1,263,076
 

2,407,361
 

Containers & Packaging - 9.1% (5.1% of total assets)

11,500

Boise Cascade Holdings, L.L.C., Term Loan B (b)

Ba3

BB

10/29/11

11,710,237
 

3,500

Boise Cascade Holdings, L.L.C., Term Loan C (b)

Ba3

BB

10/28/10

3,531,875
 

11,983

Graham Packaging Company, L.P., Term Loan B

B2

B

10/07/11

12,166,733
 

2,000

Graham Packaging Company, L.P., Term Loan C

B2

CCC+

03/15/12

2,049,584
 

7,000

Smurfit-Stone Container Corporation, New Issue Term Loan B (b)

Ba3

BB-

11/01/11

7,124,688
 

36,583,117
 

Electric Utilities - 8.8% (4.9% of total assets)

8,802

Allegheny Energy Supply Company, LLC, Term Loan (b)

B1

B+

03/08/11

8,953,948
 

6,000

Calpine Construction Finance Company, L.P., Term Loan B

B1

B+

08/31/09

6,456,000
 

10,052

Mission Energy Holdings International, Inc., Term Loan B

B3

NR

12/11/06

10,604,805
 

8,998

Reliant Energy, Inc., Term Loan B (c)

NR

NR

03/31/07

9,159,212
 

35,173,965
 

Food & Staples Retailing - 3.6% (2.0% of total assets)

5,000

Stater Brothers Holdings, Floating Rate Note, 3.500% plus three-month LIBOR

B1

BB-

06/15/10

5,100,000
 

9,000

The Jean Coutu Group Inc., Term Loan B

B1

BB

07/30/11

9,149,828
 

14,249,828
 

Healthcare Equipment & Supplies - 1.1% (0.6% of total assets)

4,305

Kinetic Concepts, Inc., Term Loan B-1

B1

BB-

08/11/10

4,360,023
 

Healthcare Providers & Services - 6.9% (3.8% of total assets)

7,647

Alderwoods Group, Inc., Term Loan B-1 (c)

B1

BB-

09/29/08

7,788,092
 

2,000

Community Health Systems, Inc., Term Loan (b)

Ba3

BB-

08/19/11

2,008,572
 

5,486

IASIS Healthcare LLC, Term Loan B

B1

B+

06/22/11

5,567,400
 

12,000

Vanguard Health Holding Company I, LLC, Term Loan B (c)

B2

B

09/23/11

12,213,756
 

27,577,820
 

Hotels, Restaurants & Leisure - 4.3% (2.4% of total assets)

6,477

Venetian Casino Resort, LLC, Term Loan B

B1

B+

06/15/11

6,597,371
 

10,701

Wyndham International, Inc., Term Loan I (c)

NR

NR

06/30/06

10,727,833
 

17,325,204
 

Household Durables - 8.1% (4.5% of total assets)

14,000

Jostens IH Corp., Term Loan B

B1

B+

07/29/10

14,227,500
 

10,000

Knoll, Inc., Term Loan

Ba3

BB-

09/29/11

10,137,500
 

7,998

Sealy Mattress Company, Term Loan C

B2

B+

08/06/12

8,112,630
 

32,477,630
 

Insurance - 2.3% (1.3% of total assets)

8,978

Conseco, Inc., Term Loan

B2

BB-

06/22/10

9,166,400
 

Machinery - 2.2% (1.2% of total assets)

8,500

Dresser-Rand Group Inc., Term Loan (b)

B1

B+

10/10/10

8,635,469
 

Marine - 1.2% (0.7% of total assets)

2,728

American Commercial Lines LLC, Term Loan B

NR

NR

06/30/06

2,729,229
 

2,232

American Commercial Lines LLC, Term Loan C

NR

NR

06/30/07

2,233,237
 

4,962,466
 

Media - 18.8% (10.4% of total assets)

18,000

Cablevision Systems Corp, Floating Rate Note, 4.500% plus six-month LIBOR

B3

B+

04/01/09

19,080,000
 

2,000

Century Cable Holdings, LLC, Discretionary Term Loan (a)

NR

NR

12/31/09

1,971,459
 

9,000

Century Cable Holdings, LLC, Revolver (a)(c)

NR

NR

10/25/10

8,836,875
 

10,000

Loews Cineplex Entertainment Corporation, Term Loan B

B1

B

06/30/11

10,137,500
 

11,000

Panamsat Corporation, Term Loan B (c)

B1

BB+

08/20/11

11,074,371
 

9,975

R.H. Donnelley Inc., Term Loan

Ba3

NR

06/30/11

10,131,902
 

5,000

Rainbow Media Holdings LLC, Term Loan (c)

Ba2

BB+

03/31/12

5,087,500
 

3,990

Regal Cinemas Corporation, Term Loan

Ba3

BB-

11/10/10

4,043,840
 

4,980

WMG Acquisition Corp., Term Loan

B1

B+

02/27/11

5,056,898
 

75,420,345
 

Metals & Mining - 1.3% (0.7% of total assets)

5,000

Amsted Industries Incorporated, Term Loan B

B1

BB-

10/15/10

5,053,125
 

Oil & Gas - 1.7% (1.0% of total assets)

5,000

Celero Energy, LP, Term Loan

NR

NR

10/01/10

5,012,500
 

1,925

Headwaters Incorporated, Term Loan B

B1

B+

04/30/11

1,948,260
 

6,960,760
 

Personal Products - 2.5% (1.4% of total assets)

9,975

Prestige Brands, Inc., Term Loan B

B1

B

04/06/11

10,076,762
 

Total Variable Rate Senior Loan Interests (cost $354,346,817)

356,346,981
 

Ratings*

Principal

Stated

Market

Amount (000)

Description(1)

Moody's

S&P

Maturity

Value

CORPORATE BONDS - 11.3% (6.3% of total assets)

Communications Equipment - 3.3% (1.8% of total assets)
$

5,000

Qwest Corporation, 6.125%

Ba3

BB-

11/15/05

$    5,125,000
 

8,000

Qwest Corporation, 6.625%

Ba3

BB-

09/15/05

8,200,000
 

13,325,000
 

Hotels, Restaurants & Leisure - 3.2% (1.8% of total assets)

815

MGM Grand, 7.250%

Ba1

BB+

10/15/06

872,050
 

6,765

Park Place Entertainment, 7.875% (c)

Ba2

BB-

12/15/05

7,111,706
 

4,440

Park Place Entertainment, 8.500%

Ba1

BB+

11/15/06

4,906,200
 

12,889,956
 

Machinery - 1.6% (0.9% of total assets)

6,000

Navistar International, Series B, 9.375%

Ba3

BB-

06/01/06

6,510,000
 

Oil & Gas - 3.2% (1.8% of total assets)

11,620

Tesoro Petroleum Corporation, 8.000%

Ba2

BBB-

04/15/08

12,694,850
 

Total Corporate Bonds (cost $45,223,461)

45,419,806
 

Principal

Market

Amount (000)

Description(1)

Value

Repurchase Agreements - 79.3% (44.0% of total assets)
$

5,025

State Street Bank, 1.740%, dated 10/29/04, due 11/01/04, repurchase price $5,025,792

$    5,025,063

   collateralized by $4,680,000 U.S. Treasury Notes, 7.000%, due 07/15/06, value $5,126,566

192,000

State Street Bank, 1.740%, dated 10/29/04, due 11/01/04, repurchase price $192,027,840

192,000,000

   collateralized by $190,520,000 U.S. Treasury Notes, 5.875%, due 11/15/04, value $195,865,991

120,000

State Street Bank, 1.740%, dated 10/29/04, due 11/01/04, repurchase price $120,017,400

120,000,000

   collateralized by $123,375,000 U.S. Treasury Bonds, 0.000%, due 03/17/05, value $122,407,740

Total Repurchase Agreements (cost $317,025,063)

317,025,063
 

Total Investments (cost $716,595,341) -- 179.6% (99.7% of total assets)

718,791,850
 

Other Assets Less Liabilities -- (19.6%)

(78,664,250)

Preferred Shares, at Liquidation Value -- (60.0%)

(240,000,000)

Net Assets Applicable to Common Shares -- 100%

$400,127,600
 

(1)  

All percentages shown in the Portfolio of Investments are based on net assets applicable to Common

shares unless otherwise noted.

(2)  

Senior Loans in which the Fund invests generally pay interest at rates which are periodically adjusted by

reference to a base short-term, floating lending rate plus a premium. These base lending rates are

generally (i) the lending rate referenced by the London Inter-Bank Offered Rate ("LIBOR"), or (ii) the

prime rate offered by one or more major United States banks.

Senior loans may be considered restricted in that the Fund ordinarily is contractually obligated to receive

approval from the Agent Bank and/or Borrower prior to the disposition of a Senior Loan.

At October 31, 2004, the Fund had unfunded loan commitments of $2,808,198.

*  

Ratings below Baa by Moody's Investor Service, Inc. or BBB by Standard & Poor's Group are

considered to be below investment grade.

**  

Senior Loans in the Fund's portfolio generally are subject to mandatory and/or optional prepayment.

Because of these mandatory prepayment conditions and because there may be significant economic

incentives for a Borrower to prepay, prepayments of Senior Loans in the Fund's portfolio may occur. As

a result, the actual remaining maturity of Senior Loans held in the Fund's portfolio may be substantially

less than the stated maturities shown. The Fund estimates that the actual average maturity of the Senior

Loans held in its portfolio will be approximately 18-24 months.

NR  

Not rated.

(a)  

At or subsequent to October 31, 2004, this issue was under the protection of the federal bankruptcy court.

(b)  

Purchased on a when-issued or delayed delivery basis.

(c)  

Portion of purchased on a when-issued or delayed delivery basis.

Income Tax Information

The following information is presented on an income tax basis. Differences between amounts for financial

statement and federal income tax purposes are primarily due to timing differences in recognizing certain

gains and losses on security transactions and recognition of premium amortization.

At October 31, 2004, the cost of investments was $716,846,325.

Gross unrealized appreciation and gross unrealized depreciation of investments at October 31, 2004,

were as follows:

Gross unrealized:

   Appreciation

$2,172,446

   Depreciation

(226,921)

Net unrealized appreciation of investments

$1,945,525

Item 2. Controls and Procedures.

  1. The registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rule 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934, (17 CFR 240.13a-15(b) or 240.15d-15(b)).
  2. There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting.

Item 3. Exhibits.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the Act (17 CFR 270.30a-2(a)), exactly as set forth below: EX-99 CERT Attached hereto.


SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant)         Nuveen Floating Rate Income Opportunity Fund        

By (Signature and Title)*          /s/ Jessica R. Droeger--Vice President and Secretary        

Date         12/30/04        

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)*         /s/ Gifford R. Zimmerman--Chief Administrative Officer (Principal Executive Officer)        

Date         12/30/04        

By (Signature and Title)*         /s/ Stephen D. Foy--Vice President and Controller (Principal Financial Officer)        

Date         12/30/04        

* Print the name and title of each signing officer under his or her signature.