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)

Kevin J. McCarthy—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:        7/31      

Date of reporting period:    4/30/2007   

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.

 

 

Nuveen Floating Rate Income Opportunity Fund (JRO)
April 30, 2007

						Weighted
Principal						Average
Amount (000)				Description (1)		Coupon		Maturity (3)		Ratings (4)		Value
				Variable Rate Senior Loan Interests – 138.5% (89.0% of Total Investments) (2)
				Aerospace & Defense – 2.3% (1.5% of Total Investments)
$	7,958			K&F Industries, Inc., Term Loan C		7.320%		11/18/12		Ba3		$	7,972,014
	1,150			Transdigm Inc., Term Loan B		7.348%		6/23/13		Ba3			1,158,194
	9,108			Total Aerospace & Defense									9,130,208
				Airlines – 3.4% (2.2% of Total Investments)
	2,000			Delta Airlines Inc., Second Lien Term Loan, WI/DD		TBD		TBD		B			2,028,750
	5,000			Northwest Airlines Inc., Term Loan		7.320%		7/19/08		BBB-			5,023,440
	6,500			United Air Lines Inc., Delayed Draw, Term Loan		7.375%		2/01/14		B+			6,510,156
	13,500			Total Airlines									13,562,346
				Auto Components – 3.2% (2.0% of Total Investments)
	1,501			Accuride Corporation, Term Loan B		7.375%		1/31/12		Ba3			1,511,662
	5,485			Federal Mogul Corporation, Revolver, (5) (6)		1.741%		2/05/05		N/R			5,210,246
	4,000			Goodyear Tire & Rubber Company, Second Lien Term Loan		7.100%		4/30/14		Ba2			4,020,630
	1,994			Lear Corporation, Term Loan		7.853%		4/12/12		B+			2,000,321
	12,980			Total Auto Components									12,742,859
				Building Products – 7.0% (4.5% of Total Investments)
	1,768			Atrium Companies Inc., Term Loan		8.518%		5/31/12		B1			1,761,862
	3,000			Building Materials Corporation of America, Second Lien Term Loan		11.125%		9/15/14		B			2,975,000
	4,988			Building Materials Corporation of America, Term Loan		8.188%		2/22/14		BB-			4,966,303
	9,750			Nortek, Inc., Term Loan B		7.365%		8/27/11		Ba2			9,791,438
	2,937			Stile Acquisition Corporation, Canadian Term Loan B		7.350%		4/05/13		BB-			2,879,208
	2,943			Stile Acquisition Corporation, Term Loan B		7.350%		4/05/13		BB-			2,884,113
	2,985			TFS Acquisition, Term Loan		8.850%		8/11/13		B+			3,007,388
	28,371			Total Building Products									28,265,312
				Capital Markets – 1.4% (0.9% of Total Investments)
	2,665			Ameritrade Holdings Corporation, Term Loan B		6.820%		12/31/12		Ba1			2,674,250
	2,786			BNY Convergex Group LLC, Term Loan		8.350%		10/02/13		B+			2,812,179
	5,451			Total Capital Markets									5,486,429
				Chemicals – 6.7% (4.4% of Total Investments)
	3,200			Celanese Holdings, LLC, Term Loan C		7.099%		4/02/14		BB-			3,220,501
	800			Celanese Holdings, LLC, Credit-Linked Deposit		5.320%		4/02/14		BB-			805,125
	1,882			Foamex LP, Term Loan B		7.597%		2/12/13		B1			1,888,628
	820			Headwaters Inc., First Lien Term Loan		7.360%		4/30/11		Ba2			822,363
	2,446			Hexion Specialty Chemicals, Inc., Term Loan C1		7.875%		5/05/13		Ba3			2,466,676
	531			Hexion Specialty Chemicals, Inc., Term Loan C2		7.875%		5/05/13		Ba3			535,832
	5,349			Huntsman International LLC, Term Loan		7.070%		8/16/12		Ba1			5,366,440
	1,272			JohnsonDiversey Inc., Term Loan		7.860%		12/16/10		Ba2			1,288,621
	1,470			Lucite International, Term Loan B		8.070%		7/07/13		Ba3			1,488,182
	519			Lucite International, Term Loan B-2, (5)		3.108%		7/07/13		Ba3			140,840
	995			Lyondell Citgo Refining LP, Term Loan		6.860%		8/16/13		BB			999,384
	7,840			Rockwood Specialties Group, Inc., Term Loan E		7.355%		7/30/12		Ba2			7,913,014
	27,124			Total Chemicals									26,935,606
				Commercial Services & Supplies – 3.0% (1.9% of Total Investments)
	2,784			Allied Waste North America, Inc., Letter of Credit		7.073%		1/15/12		BB			2,800,317
	6,277			Allied Waste North America, Inc., Term Loan B		7.097%		1/15/12		BB			6,311,567
	828			Cenveo Inc., Term Loan B		7.100%		6/21/13		Ba3			828,879
	28			Cenveo Inc., Delayed Draw, Term Loan B		7.100%		6/21/13		Ba3			27,629
	998			NCO Group Inc., Term Loan		8.355%		5/15/13		Ba3			1,005,293
	1,021			Workflow Management, Inc., Term Loan		9.355%		11/30/11		BB-			1,020,657
	11,936			Total Commercial Services & Supplies									11,994,342
				Communications Equipment – 1.1% (0.7% of Total Investments)
	2,985			Aspect Software, Term Loan B		8.375%		7/11/11		Ba3			3,016,093
	427			Valassis Communications, Inc., Delayed Draw, Term Loan, (5) (7)		1.000%		3/02/14		Ba2			(267	)
	1,573			Valassis Communications, Inc., Term Loan		7.100%		3/02/14		Ba2			1,576,939
	4,985			Total Communications Equipment									4,592,765
				Consumer Finance – 0.5% (0.3% of Total Investments)
	1,988			Peach Holdings Inc., Term Loan		9.100%		11/30/13		B			2,004,891
				Containers & Packaging – 6.7% (4.4% of Total Investments)
	990			Amscan Holdings Inc., Term Loan B		8.385%		4/30/12		Ba3			998,972
	686			Bluegrass Container Company LLC, Delayed Draw, First Lien Term Loan		7.589%		6/30/13		BB-			694,176
	3,030			Bluegrass Container Company, LLC, Delayed Draw, Second Lien Term Loan		10.320%		12/31/13		BB-			3,092,424
	970			Bluegrass Container Company, LLC, Delayed Draw, Second Lien Term Loan		10.320%		12/31/13		B-			989,576
	2,292			Bluegrass Container Company, LLC, Term Loan B		7.591%		6/30/13		BB-			2,320,011
	13,739			Graham Packaging Company, L.P., Term Loan B		7.625%		2/14/10		B1			13,838,867
	611			Smurfit-Stone Container Corporation, Deposit-Funded Commitment		7.748%		11/01/11		Ba2			616,624
	2,416			Smurfit-Stone Container Corporation, Term Loan B		7.531%		11/01/11		Ba2			2,437,363
	1,469			Smurfit-Stone Container Corporation, Term Loan C		7.546%		11/01/11		Ba2			1,482,173
	461			Smurfit-Stone Container Corporation, Tranche C-1		7.375%		11/01/11		Ba2			465,140
	26,664			Total Containers & Packaging									26,935,326
				Diversified Consumer Services – 0.8% (0.5% of Total Investments)
	3,245			West Corporation, Term Loan		7.750%		10/24/13		B+			3,271,899
				Diversified Telecommunication Services – 6.3% (4.0% of Total Investments)
	4,000			Cequel Communications LLC., Term Loan B		7.349%		11/05/13		B+			4,000,500
	1,000			Choice One Communications, Term Loan B		9.375%		6/27/12		Ba3			1,015,000
	1,000			Choice One Communications, Term Loan B		8.875%		6/30/12		B1			1,015,000
	3,000			Crown Castle International Corporation, Term Loan		6.893%		1/26/14		BB+			3,009,024
	1,965			Intelsat Corporation, Term Loan		7.349%		7/01/13		Ba2			1,981,092
	2,000			Intelsat Corporation, Unsecured Term Loan		7.860%		2/01/14		BB			2,009,643
	3,500			Iowa Telecommunications Services, Inc., Term Loan B		7.098%		11/23/11		BB-			3,523,697
	4,533			Level 3 Communications Incorporated, Term Loan		7.605%		3/13/14		B1			4,553,876
	3,980			MetroPCS Inc., Term Loan		7.625%		11/03/13		B1			4,010,348
	24,978			Total Diversified Telecommunication Services									25,118,180
				Electric Utilities – 3.3% (2.1% of Total Investments)
	8,889			Calpine Corporation, DIP Term Loan		7.590%		3/29/09		N/R			8,945,369
	1,111			Calpine Corporation, DIP Revolver, (5) (7)		0.250%		3/29/09		N/R			(16,667	)
	188			MACH Gen LLC, Synthetic Letter of Credit		7.350%		2/22/13		B			187,764
	1,808			MACH Gen LLC, Term Loan		7.360%		2/22/14		B			1,809,777
	2,159			Murray Energy Corporation, Term Loan C		13.860%		1/28/11		N/R			2,304,199
	14,155			Total Electric Utilities									13,230,442
				Electrical Equipment – 0.4% (0.2% of Total Investments)
	1,485			Generac Inc., Term Loan		7.850%		11/10/13		B1			1,487,228
				Electronic Equipment & Instruments – 0.5% (0.3% of Total Investments)
	1,985			Sensata Technologies B.V., Term Loan		7.105%		4/27/13		BB-			1,986,297
				Energy Equipment & Services – 0.1% (0.0% of Total Investments)
	287			Petroleum Geo-Services, Term Loan		7.600%		12/15/12		BB-			288,911
				Food & Staples Retailing – 1.9% (1.2% of Total Investments)
	7,684			Jean Coutu Group, Inc., Term Loan B		7.875%		7/30/11		BB-			7,702,150
				Food Products – 1.7% (1.1% of Total Investments)
	651			Dole Foods Company Inc., Deposit-Funded Commitment		7.356%		4/12/13		Ba3			651,253
	1,450			Dole Foods Company Inc., Term Loan B		7.541%		4/12/13		Ba3			1,450,667
	4,835			Dole Foods Company Inc., Term Loan C		7.456%		4/12/13		Ba3			4,835,555
	6,936			Total Food Products									6,937,475
				Health Care Equipment & Supplies – 0.3% (0.2% of Total Investments)
	1,337			Kinetic Concepts Inc., Term Loan B-1		6.850%		8/11/10		Ba1			1,339,641
				Health Care Providers & Services – 11.4% (7.5% of Total Investments)
	7,147			Community Health Systems, Inc., Term Loan		7.100%		8/19/11		BB-			7,173,206
	3,834			Davita Inc., Term Loan B		6.842%		10/05/12		Ba1			3,849,220
	4,988			HCA, Inc., Term Loan		7.600%		11/17/13		BB			5,045,460
	5,000			Health Management Associates, Term Loan		7.100%		2/28/14		Ba2			5,025,520
	3,970			HealthSouth Corporation, Term Loan		7.847%		3/10/13		B+			4,002,256
	1,276			IASIS Healthcare LLC, Delayed Draw, Term Loan, WI/DD		TBD		TBD		Ba2			1,280,320
	340			IASIS Healthcare LLC, Letter of Credit, WI/DD		TBD		TBD		Ba2			341,419
	3,733			IASIS Healthcare LLC, Term Loan, WI/DD		TBD		TBD		Ba2			3,747,071
	1,010			LifePoint Hospitals Holdings, Inc., Term Loan B		6.985%		4/15/14		BB-			1,008,910
	14,673			Vanguard Health Holding Company, LLC, Replacement Term Loan		7.600%		9/23/11		Ba3			14,786,066
	45,971			Total Health Care Providers & Services									46,259,448
				Health Care Technology – 0.5% (0.3% of Total Investments)
	1,982			Emdeon Business Services, Term Loan		7.600%		11/16/13		B+			1,992,902
				Hotels, Restaurants & Leisure – 8.1% (5.2% of Total Investments)
	3,962			24 Hour Fitness Worldwide, Inc., Term Loan B		7.850%		7/01/09		Ba3			3,989,723
	488			CBRL Group, Inc., Delayed Draw, Term Loan B-2, (5) (7)		0.750%		4/27/13		BB			(204	)
	2,978			Cedar Fair LP, Term Loan		7.320%		8/30/12		BB-			3,009,136
	1,927			Green Valley Ranch Gaming, Term Loan B		7.360%		2/16/14		B+			1,939,662
	3,781			Intrawest Corporation, Term Loan		9.250%		12/31/07		N/R			3,790,690
	1,970			Penn National Gaming, Inc., Term Loan B		7.114%		10/03/12		BB			1,986,006
	7,250			Travelport, Term Loan		7.850%		8/23/13		Ba3			7,321,468
	714			Travelport, Letter of Credit		7.850%		8/23/13		Ba3			720,833
	1,282			Venetian Casino Resort, LLC Term Loan B		7.090%		6/15/11		BB-			1,288,585
	6,218			Venetian Casino Resort, LLC, Term Loan		7.090%		6/15/11		BB-			6,249,638
	1,995			Worldspan LP, Term Loan		8.600%		12/07/13		Ba3			2,005,224
	32,565			Total Hotels, Restaurants & Leisure									32,300,761
				Household Durables – 1.6% (1.0% of Total Investments)
	6,200			Jarden Corporation, Term Loan		7.100%		1/24/12		Ba2			6,220,428
				Household Products – 2.4% (1.5% of Total Investments)
	9,527			Prestige Brands, Inc., Term Loan B		7.634%		4/06/11		Ba3			9,586,175
				Insurance – 1.6% (1.0% of Total Investments)
	998			Affirmative Insurance Holdings Inc., Term Loan		8.829%		2/01/14		B1			1,003,111
	5,421			Conseco, Inc., Term Loan		7.320%		10/10/13		BB-			5,453,035
	6,419			Total Insurance									6,456,146
				Internet Software & Services – 1.0% (0.6% of Total Investments)
	4,000			Sabre Group Holdings, Inc., Term Loan		7.605%		9/30/14		B+			4,013,124
				IT Services – 3.1% (2.0% of Total Investments)
	1,000			Attachmate, Term Loan		8.590%		6/01/13		B1			1,004,167
	341			Infor Global Solutions, Delayed Draw, Term Loan		9.100%		7/28/12		B1			343,275
	654			Infor Global Solutions, Term Loan		9.100%		4/18/11		B1			659,415
	10,263			SunGard Data Systems Inc., Term Loan B		7.360%		2/28/14		Ba3			10,363,096
	12,258			Total IT Services									12,369,953
				Leisure Equipment & Products – 1.4% (0.9% of Total Investments)
	5,468			Bombardier Recreational Products, Term Loan		7.860%		6/28/13		BB			5,511,079
				Machinery – 1.3% (0.8% of Total Investments)
	1,589			Navistar International, Term Loan		8.610%		1/31/12		BB-			1,613,053
	578			Navistar International Synthetic Letter of Credit		8.208%		1/19/12		BB-			586,565
	1,995			Oshkosh Truck Corporation, Term Loan		7.100%		12/06/13		BB			2,003,417
	967			Rexnord Corporation, Term Loan		7.858%		7/19/13		Ba2			975,525
	5,129			Total Machinery									5,178,560
				Media – 25.2% (16.4% of Total Investments)
	1,975			AMC Entertainment Inc., Term Loan		7.070%		1/26/13		Ba1			1,986,771
	2,500			American Lawyer Media, Inc., Second Lien Term Loan		11.100%		3/07/11		Caa1			2,508,334
	757			Blockbuster, Inc., Term Loan A		8.377%		8/20/09		B1			760,611
	2,707			Blockbuster, Inc., Term Loan B		8.631%		8/20/11		B1			2,740,155
	3,000			Charter Communications Operating, LLC, Term Loan		7.850%		9/06/14		B1			3,006,251
	1,000			Charter Communications Operating, LLC, Term Loan		7.350%		9/06/14		B1			999,766
	4,938			Clear Channel Entertainment, Term Loan B		8.089%		6/20/13		B+			4,962,188
	952			Cumulus Media Inc, Term Loan		7.323%		6/07/13		Ba3			958,344
	2,000			HIT Entertainment Inc., Second Lien Term Loan		10.820%		2/26/13		B3			2,028,126
	3,940			HIT Entertainment Inc., Term Loan B		7.590%		3/20/12		Ba3			3,968,319
	4,988			Idearc Inc., Term Loan		7.350%		11/17/14		BB+			5,026,333
	3,000			Metro-Goldwyn-Mayer Studios, Inc., Term Loan		8.600%		4/08/12		B+			3,006,798
	3,955			Metro-Goldwyn-Mayer Studios, Inc., Term Loan B		8.600%		4/08/12		B+			3,963,987
	8,955			Neilsen Finance LLC, Term Loan B		7.610%		8/09/13		Ba3			9,043,619
	3,000			NextMedia Operating Inc., Second Lien Term Loan		9.820%		11/15/12		CCC+			3,019,688
	10,945			Panamsat Corporation, Term Loan		7.349%		7/03/13		BB			11,043,166
	3,000			Philadelphia Newspapers, Mezzanine Term Loan		16.000%		6/29/12		N/R			3,007,500
	2,000			ProQuest Company, Term Loan B		8.332%		2/09/14		N/R			2,003,750
	4,810			R. H. Donnelley Inc., Term Loan D-2		6.851%		6/30/11		Ba1			4,818,909
	3,891			Regal Cinemas Corporation, Term Loan		7.100%		10/27/13		Ba2			3,907,858
	906			Univision Communications, Delayed Draw, Term Loan, (5) (7)		1.000%		9/29/14		Ba3			(695	)
	2,000			Univision Communications, Second Lien Term Loan		7.820%		3/29/09		B3			2,002,083
	14,094			Univision Communications, Term Loan		7.605%		9/15/14		Ba3			14,083,150
	2,000			UPC Broadband Holding BV, Term Loan J2		7.370%		3/29/13		Ba3			2,004,285
	2,000			UPC Broadband Holding BV, Term Loan K2		7.370%		12/31/13		Ba3			2,004,285
	4,839			WMG Acquisition Corp., Term Loan		7.359%		2/28/11		Ba2			4,863,415
	4,025			Yell Group, Term Loan		7.320%		10/27/12		Ba3			4,061,134
	102,177			Total Media									101,778,130
				Metals & Mining – 1.9% (1.2% of Total Investments)
	2,541			Amsted Industries Incorporated, Delayed Draw Term Loan		7.350%		4/05/11		BB-			2,547,037
	3,496			Amsted Industries Incorporated, Term Loan B		7.350%		4/05/13		BB-			3,509,253
	1,553			Freeport McMoran Copper and Gold, Term Loan		7.070%		3/19/14		Baa3			1,559,178
	7,590			Total Metals & Mining									7,615,468
				Multi-Utilities – 2.0% (1.3% of Total Investments)
	5,721			NRG Energy Inc., Term Loan		7.350%		2/01/13		Ba1			5,770,944
	2,365			NRG Energy Inc., Credit-Linked Deposit		7.350%		2/01/13		Ba1			2,385,508
	8,086			Total Multi-Utilities									8,156,452
				Oil, Gas & Consumable Fuels – 2.0% (1.3% of Total Investments)
	4,000			Callon Petroleum, Term Loan, WI/DD		TBD		TBD		N/R			3,980,000
	301			Coffeyville Resources LLC, Letter of Credit		8.249%		5/10/10		B+			304,981
	1,549			Coffeyville Resources LLC., Term Loan		8.350%		12/28/13		B+			1,570,507
	2,000			El Paso Corporation, Letter of Credit		7.320%		7/31/11		Ba1			2,012,188
	7,850			Total Oil, Gas & Consumable Fuels									7,867,676
				Paper & Forest Products – 4.6% (3.0% of Total Investments)
	3,486			Boise Cascade Corporation, Term Loan D		7.070%		3/29/11		BB			3,501,628
	7,900			Georgia-Pacific Corporation, Term Loan B		7.091%		12/20/10		Ba2			7,947,921
	3,109			Georgia-Pacific Corporation, Term Loan B-2		7.090%		12/20/12		Ba2			3,128,897
	2,892			Ply Gem Industries Inc., Term Loan B3		8.100%		8/15/11		B+			2,893,739
	108			Ply Gem Industries Inc., Canadian Term Loan		8.100%		8/15/11		B+			108,136
	1,000			White Birch Paper Company, Second Lien Term Loan		12.820%		4/08/13		CCC+			1,017,813
	18,495			Total Paper & Forest Products									18,598,134
				Pharmaceuticals – 0.1% (0.0% of Total Investments)
	279			Rexnord Corporation, Term Loan		7.580%		7/19/13		Ba2			280,918
				Real Estate Investment Trust – 0.3% (0.2% of Total Investments)
	998			Landsource Community Development, Term Loan		8.070%		2/27/13		BB+			1,004,748
				Real Estate Management & Development – 4.5% (2.9% of Total Investments)
	4,563			Capital Automotive LP., Term Loan		7.070%		12/16/10		BB+			4,607,732
	9,500			LNR Property Corporation, Term Loan B		8.110%		7/12/11		B+			9,566,158
	2,000			Promontory Club, Second Lien Term Loan		11.820%		8/31/11		N/R			1,965,000
	1,955			Promontory Club, Term Loan B		8.070%		8/31/10		N/R			1,949,625
	18,018			Total Real Estate Management & Development									18,088,515
				Road & Rail – 0.7% (0.5% of Total Investments)
	444			Hertz Corporation, Synthetic Term Loan		5.365%		12/21/12		BB+			448,038
	2,483			Hertz Corporation, Term Loan B		7.082%		12/21/12		Ba1			2,502,742
	2,927			Total Road & Rail									2,950,780
				Semiconductors & Equipment – 1.9% (1.2% of Total Investments)
	5,433			Advanced Micro Devices, Term Loan B		7.340%		12/31/13		BB-			5,447,845
	1,995			Freescale Semiconductor, Term Loan		7.110%		3/30/14		Baa3			2,000,663
	7,428			Total Semiconductors & Equipment									7,448,508
				Software – 2.8% (1.8% of Total Investments)
	4,000			Dealer Computer Service, Second Lien Term Loan		10.850%		10/26/13		BB-			4,103,750
	6,965			Dealer Computer Service, Term Loan		7.350%		10/26/12		Ba2			7,004,178
	10,965			Total Software									11,107,928
				Specialty Retail – 6.0% (3.8% of Total Investments)
	983			Burlington Coat Factory Warehouse Corporation, Term Loan		7.610%		5/28/11		B			978,386
	3,960			FGX International Inc., Term Loan B		9.350%		12/09/12		B1			3,969,900
	6,820			Michaels Stores Inc., Term Loan		8.125%		10/31/13		B2			6,882,059
	1,990			Sally Beauty, Term Loan		7.860%		11/16/13		BB-			2,008,103
	7,000			TRU 2005 RE Holding Co. l, Term Loan		8.320%		12/09/08		B3			7,064,533
	3,000			Toys “R” Us, Inc., Term Loan B		9.610%		7/19/12		Ba3			3,075,563
	23,753			Total Specialty Retail									23,978,544
				Textiles, Apparel & Luxury Goods – 3.0% (1.9% of Total Investments)
	1,852			HanesBrands Inc., Term Loan		7.105%		9/05/13		Ba2			1,864,981
	1,000			HanesBrands Inc., Second Lien Term Loan		9.105%		3/05/14		B1			1,025,782
	8,942			Visant Holding Corporation, Term Loan C		7.330%		7/29/10		B+			8,997,550
	11,794			Total Textiles, Apparel & Luxury Goods									11,888,313
				Trading Companies & Distributors – 0.5% (0.3% of Total Investments)
	2,000			Ashtead Group Public Limited Company, Term Loan B		7.125%		8/31/11		BB			2,000,000
$	556,078			Total Variable Rate Senior Loan Interests (cost $552,861,729)									555,664,997

Principal
Amount (000)				Description (1)		Coupon		Maturity		Ratings (4)		Value
				Corporate Bonds – 16.9% (10.9% of Total Investments)
				Diversified Telecommunication Services – 3.1% (2.0% of Total Investments)
$	1,500			Intelsat Bermuda Limited, Floating Rate Note, 3.500% plus six-month LIBOR, 144A		8.860%		1/15/15		B		$	1,541,250
	10,000			Qwest Corporation, Floating Rate Note, 3.250% plus three-month LIBOR		8.605%		6/15/13		N/R			10,987,500
	11,500			Total Diversified Telecommunication Services									12,528,750
				Electronic Equipment & Instruments – 2.8% (1.8% of Total Investments)
	11,000			NXP BV, Floating Rate Note, 2.750% plus three-month LIBOR, 144A		8.105%		10/15/13		BB+			11,412,500
				Food & Staples Retailing – 2.5% (1.6% of Total Investments)
	10,000			Stater Brothers Holdings Inc., Floating Rate Note, 3.500% plus three-month LIBOR		8.855%		6/15/10		B+			10,162,500
				Health Care Equipment & Supplies – 0.4% (0.3% of Total Investments)
	1,500			Encore Medical Finance LLC, 144A		11.750%		11/15/14		CCC+			1,578,750
				Media – 4.1% (2.7% of Total Investments)
	15,000			Cablevision Systems Corporation, Floating Rate Note, 4.500% plus six-month LIBOR, Series B, 144A		9.860%		4/01/09		B+			15,975,000
				Paper & Forest Products – 0.5% (0.3% of Total Investments)
	2,000			Verso Paper Holdings LLC., 144A		9.125%		8/01/14		B			2,115,000
				Real Estate Investment Trust – 0.8% (0.5% of Total Investments)
	3,000			Felcor Lodging Trust Inc., Floating Rate Note, 1.875% plus six-month LIBOR, 144A		7.235%		12/01/11		Ba3			3,045,000
				Semiconductors & Equipment – 1.3% (0.8% of Total Investments)
	5,000			Avago Technologies Finance Pte. Ltd., Floating Rate Note, 5.500% plus three-month LIBOR, 144A		10.855%		6/01/13		B			5,250,000
				Trading Companies & Distributors – 1.4% (0.9% of Total Investments)
	3,000			Neff Rental LLC/Neff Finance Corporation		11.250%		6/15/12		B-			3,495,000
	2,000			Penhall International Corporation, 144A		12.000%		8/01/14		B3			2,200,000
	5,000			Total Trading Companies & Distributors									5,695,000
$	64,000			Total Corporate Bonds (cost $64,511,642)									67,762,500

Shares				Description (1)								Value
				Warrants – 0.1% (0.1% of Total Investments)
	26,182			Reliant Energy Inc.								$	424,148
				Total Warrants (cost $184,678)									424,148
				Total Investments (cost $617,558,049) – 155.5%									623,851,645
				Other Assets Less Liabilities – 4.3%									17,297,497
				Preferred Shares, at Liquidation Value – (59.8)%									(240,000,000	)
				Net Assets Applicable to Common Shares – 100%								$	401,149,142

(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 an assigned fixed rate. These floating 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.
(3)		Senior Loans 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 may occur. As a result, the actual remaining maturity of Senior Loans held may be substantially less than the stated maturities shown.
(4)		Ratings: Using the higher of Standard & Poor’s or Moody’s rating. Ratings below BBB by Standard & Poor’s Group or Baa by Moody’s Investor Service, Inc. are considered to be below investment grade.
(5)		Position or portion of position represents an unfunded Senior Loan commitment outstanding at April 30, 2007. At April 30, 2007, the Fund had unfunded Senior Loan commitments of $3,318,103.
(6)		At or subsequent to April 30, 2007, this issue was under the protection of the Federal Bankruptcy Court.
(7)		Negative value represents unrealized depreciation on Senior Loan commitment at April 30, 2007.
N/R		Not rated.
WI/DD		Purchased on a when-issued or delayed delivery basis.
144A		Investment is exempt from registration under Rule 144A of the Securities Act of 1933, as amended. These investments may only be resold in transactions exempt from registration which are normally those transactions with qualified institutional buyers.
TBD		Senior Loan purchased on a when-issued or delayed-delivery basis. Certain details associated with this purchase are not known prior to the settlement date of the transaction. In addition, Senior Loans typically trade without accrued interest and therefore a weighted average coupon rate is not available prior to settlement. At settlement, if still unknown, the Borrower or counterparty will provide the Fund with the final weighted average coupon rate and maturity date.

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 the treatment of paydown gains and losses, recognition of premium amortization and timing differences in recognizing certain gains and losses on investment transactions.

At April 30, 2007, the cost of investments was $618,191,010.

Gross unrealized appreciation and gross unrealized depreciation of investments at April 30, 2007, were as follows:

Gross unrealized:
Appreciation		$	6,361,807
Depreciation			(701,172	)
Net unrealized appreciation (depreciation) of investments		$	5,660,635

Item 2. Controls and Procedures.

	a.		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)).
	b.		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 have materially affected, or are 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 1940 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               

Date June 29, 2007

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.

Date June 29, 2007

Date June 29, 2007