Largest Lakes in Wisconsin

50 Wisconsin lakes with measured surface area, ranked by acreage. The biggest lake in Wisconsin is Pepin Lake, which tops the list at 24,550 acres in Pepin County.

Lakes with area data

24,550

Largest (acres)

3,483

Median of top 50

18/50

Reservoirs (vs natural)

Reading Wisconsin's size profile

Wisconsin's largest lake by surface area is Pepin Lake in Pepin County, spanning 24,550 acres and reaching 60 ft deep. Most of Wisconsin's biggest waters are natural basins left by glaciers, with stable shorelines and deep main basins.

Surface area is a poor proxy for water quality on its own — a large lake can hold a clean, deep core and a nutrient-loaded bay at the same time. Each lake below links to its full report card with grade, clarity, depth, and EPA impairment status. Area figures come from state DNR surveys and the USACE National Inventory of Dams; grades come from EPA and state monitoring data.

The 50 biggest lakes in Wisconsin by surface area

#	Lake	County	Surface area	Max depth	Grade
1	Pepin Lake	Pepin	24,550 acres	60 ft	F
2	Petenwell Flowage Lake	Juneau	23,173 acres	44 ft	D
3	Chippewa Flowage Lake	Sawyer	14,593 acres	92 ft	B
4	Lake Poygan	Winnebago	14,024 acres	11 ft	F
5	Turtle Flambeau Flowage Lake	Iron	13,798 acres	-	B
6	Turtle-Flambeau Flowage Lake	Iron	12,942 acres	50 ft	D
7	Lake Koshkonong	Jefferson	10,595 acres	7 ft	F
8	Lake Mendota	Dane	9,781 acres	83 ft	C
9	Lake Butte des Morts	Winnebago	8,581 acres	9 ft	F
10	Green Lake	Green Lake	7,920 acres	236 ft	B
11	Lake Dubay	Marathon	7,800 acres	-	D
12	Lake St. Croix	St. Croix	7,696 acres	60 ft	B
13	Lake	Columbia	7,197 acres	24 ft	F
14	Lake Wisconsin Palisade Street Bay	Sauk	7,197 acres	24 ft	F
15	Beaver Dam Lake	Dodge	6,542 acres	-	F
16	Big Eau Pleine Southeast Point Lake	Marathon	6,348 acres	46 ft	F
17	Shawano Lake	Shawano	6,215 acres	39.5 ft	C
18	Moon Bay Lake	Chippewa	6,148 acres	64.4 ft	D
19	Geneva Lake	Walworth	5,401 acres	135 ft	A
20	Lac Courte Oreilles Lake	Sawyer	5,139 acres	90 ft	A
21	Lake Puckaway	Green Lake	5,013 acres	5 ft	C
22	Lake Winneconne	Winnebago	4,553 acres	9 ft	F
23	Holcombe Flowage Lake	Chippewa	4,300 acres	-	C
24	Lac Vieux Desert Lake	Vilas	4,017 acres	38 ft	C
25	Pelican Lake	Oneida	3,545 acres	39 ft	D
26	Fence Lake Deep	Vilas	3,483 acres	86 ft	A
27	Gile Flowage Lake	Iron	3,317 acres	-	C
28	Round Lake	Sawyer	3,294 acres	74 ft	A
29	Long Lake	Washburn	3,290 acres	-	B
30	Lake Kegonsa	Dane	3,200 acres	32 ft	C
31	Grindstone Lake	Sawyer	3,176 acres	60 ft	A
32	North Twin Lake	Vilas	2,871 acres	60 ft	B
33	Rush Lake	Winnebago	2,729 acres	5 ft	C
34	Fox Lake	Dodge	2,713 acres	19 ft	F
35	Shell Lake	Washburn	2,513 acres	36 ft	A
36	Nelson Lake	Sawyer	2,503 acres	-	C
37	Pewaukee Lake	Waukesha	2,437 acres	45 ft	B
38	Lake Chetac North Basin	Sawyer	2,400 acres	26 ft	C
39	Lake Noquebay	Marinette	2,398 acres	51 ft	B
40	Chequamegon Waters Flowage Lake	Taylor	2,366 acres	22 ft	F
41	Yellow Lake	Burnett	2,283 acres	31 ft	C
42	Lake Nokomis	Oneida	2,274 acres	33 ft	C
43	Muskego Lake	Waukesha	2,194 acres	23 ft	C
44	Buffalo Lake	Marquette	2,179 acres	8 ft	F
45	Lake Waubesa	Dane	2,074 acres	38 ft	D
46	Lake Metonga	Forest	2,038 acres	79 ft	A
47	Saint Croix Flowage Lake	Douglas	1,913 acres	-	B
48	Delavan Lake	Walworth	1,906 acres	52 ft	B
49	Balsam Lake	Polk	1,901 acres	37 ft	B
50	Red Cedar Lake	Barron	1,897 acres	53 ft	A

Frequently Asked Questions

What is the largest lake in Wisconsin?

The largest lake in Wisconsin in the LakeGrade dataset is Pepin Lake in Pepin County at 24,550 acres. Water quality grade: F, with a maximum depth of 60 ft.

How is lake surface area measured?

Surface area comes from state DNR lake surveys and, for reservoirs, US Army Corps of Engineers (USACE) National Inventory of Dams records. Area is reported in acres at normal pool level. Reservoirs rise and fall with management and drought, so their listed area is the long-term normal rather than a single-day reading.

Are Wisconsin's largest lakes natural or reservoirs?

Of the top 50 Wisconsin lakes by area, 18 sit on a dammed river (reservoirs) and 32 are natural basins. Glacial states (MN, WI, MI, NY) skew natural; plains and southern states (MO, IA, ND, OH) skew toward reservoirs built for water supply, flood control, and recreation.

Do larger lakes have better water quality?

Not reliably. Quality varies more within a big lake than between lakes — a large lake can have a clean, deep main basin and a murky, algae-prone bay fed by a tributary, so one grade can mask wide swings. Depth, watershed land use, and how fast the lake flushes matter far more than raw surface area.

How big is the typical Wisconsin lake in this ranking?

Across the top 50 Wisconsin lakes by surface area, the median is 3,483 acres (Fence Lake Deep). This list is biased toward the biggest waters; the typical Wisconsin lake is far smaller.

Where to stay near Wisconsin's largest lakes

Planning a trip? Jump to live cabin, resort, and hotel availability near Wisconsin's biggest lakes.

Deepest lakes in Wisconsin →Cleanest lakes in Wisconsin →Largest lakes (all states) →All Wisconsin lakes →