Fond du Lac County, Wisconsin

Fond du Lac County is a county in Wisconsin, United States, about 60 miles north of Milwaukee via I-41. It had a population of 104,154 at the 2020 census, an estimated 104,669 by 2024, and covers 766 square miles (1,980 km2) centred near 43°46′N 88°29′W.

Fond du Lac is the county seat and the county’s largest city; its postal code is 54935. The county holds 3 cities, 9 villages and 21 towns, plus 4 census-designated places and more than 50 unincorporated communities, and it runs on Central Time. Its FIPS code is 55039.

Towns & Villages in Fond du Lac County

Fond du Lac County has 16 places tracked with individual 2020 census figures: 3 cities, 9 incorporated villages and 4 census-designated places (CDPs), which are unincorporated but recognized and counted separately by the Census Bureau. Beyond these, more than 50 smaller unincorporated hamlets and lakeshore subdivisions have no population of their own on record.

Two places need explaining. Waupun straddles the Dodge–Fond du Lac county line; the city’s full 2020 population was 11,344, but only 3,549 of those residents live in the Fond du Lac County portion, the figure used above. Kewaskum, a village of 4,309 people, also crosses into the northeast corner of Fond du Lac County, but every one of its residents lives on the Washington County side, so it carries no population here and is not listed in the table.

Townships

Wisconsin’s “towns” are unincorporated civil townships, the local government layer that covers the county outside its cities and villages. Fond du Lac County has 21 of them.

Several more unincorporated lakeshore subdivisions — small platted communities along Lake Winnebago in the towns of Calumet and Taycheedah — have no population figures of their own on record and are not listed above.

ZIP Codes

• 54935 — Fond du Lac (the county’s most populous ZIP)
• 54936 — Fond du Lac (PO box ZIP)
• 54937 — Fond du Lac and North Fond du Lac
• 54971 — Ripon
• 53963 — Waupun
• 53010 — Campbellsport
• 53065 — Oakfield
• 54974 — Rosendale
• 53019 — Eden
• 53919 — Brandon
• 53057 — Mount Calvary
• 53079 — St. Cloud
• 53931 — Fairwater
• 54979 — Van Dyne
• 54932 — Eldorado

St. Peter, Taycheedah and Alto have no ZIP code of their own; mail there is delivered under a neighboring town’s code. Malone, an unincorporated community split between the towns of Marshfield and Byron, keeps its own ZIP, 53049, even though it has no separate population count in the places table above.

Geography

Fond du Lac County sits at the southern end of Lake Winnebago, Wisconsin’s largest inland lake, in the state’s east-central region. Of its 766 square miles, 720 are land and 46 are water — about 6.0 percent, most of it Lake Winnebago itself. The Fond du Lac River, Milwaukee River, Rock River and Sheboygan River all rise in or cross the county. The Northern Kettle Moraine, a belt of glacially formed hills and lakes, runs through the county’s southeastern towns, including Ashford and Auburn.

Winnebago County lies to the north, Calumet County to the northeast, Sheboygan County to the east, Washington County to the southeast, Dodge County to the southwest, and Green Lake County to the west. Winnebago County, Calumet County, Sheboygan County, Washington County, Dodge County and Green Lake County all border Fond du Lac directly.

Demographics

Fond du Lac County had a population of 104,154 at the 2020 census, and the latest estimate puts the county near 104,669 residents. Fond du Lac and Ripon are the two largest communities, together holding roughly half the county’s population. Median household income runs $74,275, close to Wisconsin’s statewide figure of $74,631. Population density works out to about 144.7 people per square mile of land, moderate for a Wisconsin county that includes one small city and a large lakeshore.

Economy & Local Life

Manufacturing employs the most workers in the county, about 12,606 people, followed by health care and social assistance at 6,764 and retail trade at 5,486. Mercury Marine, the world’s largest outboard motor manufacturer, employs roughly 2,500 people at its Fond du Lac plant, the county’s single biggest private employer. Saputo Cheese, Brenner Tank, Giddings & Lewis, Chicago Tube & Iron and J.F. Ahern all run major operations in Fond du Lac as well. Marian University and Moraine Park Technical College serve the city, and St. Agnes Hospital anchors regional health care; Ripon College, a liberal arts school founded in 1851, sits in Ripon. The county’s biggest annual event is Walleye Weekend, held the second weekend of June on Fond du Lac’s lakefront to mark the opening of walleye season on Lake Winnebago.

History

Wisconsin Territory authorized Fond du Lac County in 1836, and it was organized as a functioning county government in 1844. The name is French for “bottom of the lake,” describing its position at the southern shore of Lake Winnebago. Fond du Lac itself was incorporated as a village in 1847 and as a city in 1852.

On 20 March 1854, about 30 opponents of the Kansas–Nebraska Act met at a one-room schoolhouse in Ripon and called for a new political party opposed to the expansion of slavery. That meeting is recognized as the founding of the Republican Party, and the Little White Schoolhouse still stands in Ripon today.

Getting There

Interstate 41 runs the length of the county through Fond du Lac and North Fond du Lac. US 41, US 45 and US 151 also cross the county, along with Wisconsin 23, 44, 49 and 175.

• Milwaukee — about 60 miles south
• Oshkosh — about 20 miles north
• Green Bay — about 65 miles north
• Madison — about 65 miles southwest

Fond du Lac County Airport, a mile west of downtown Fond du Lac, handles general aviation only and serves as an overflow parking site for the EAA AirVenture Oshkosh air show each July. Appleton International Airport, roughly 30 miles north, is the nearest airport with scheduled commercial flights; Milwaukee Mitchell International, about 60 miles south, offers more routes. Amtrak’s Empire Builder and Borealis trains stop at Columbus, roughly 45 miles southwest, the nearest station to the county.

Frequently Asked Questions

Where is Fond du Lac County located?
It sits at the southern end of Lake Winnebago in east-central Wisconsin, about 60 miles north of Milwaukee, bordered by Winnebago, Calumet, Sheboygan, Washington, Dodge and Green Lake counties.

What is the population of Fond du Lac County?
104,154 at the 2020 census, with a 2024 estimate near 104,669.

How big is Fond du Lac County?
766 square miles (1,980 km2), of which 720 square miles are land and 46 square miles are Lake Winnebago and other water.

What is the county seat of Fond du Lac County?
Fond du Lac, incorporated as a city in 1852, is the county seat and largest city.

How many towns and villages are in Fond du Lac County?
3 cities — Fond du Lac, Ripon and Waupun (partly) — 9 villages, 4 census-designated places, and 21 towns (civil townships), plus more than 50 smaller unincorporated communities.

What ZIP codes does Fond du Lac County use?
54935, 54936 and 54937 for Fond du Lac and North Fond du Lac; 54971 for Ripon; 53963 for Waupun; and separate codes for each of the smaller villages, from 53010 in Campbellsport to 54979 in Van Dyne.

What is Fond du Lac County known for?
Mercury Marine’s outboard-motor plant, Walleye Weekend on Lake Winnebago each June, and Ripon’s Little White Schoolhouse, where the Republican Party was founded in 1854.

More counties in this state: Towns and villages in Wisconsin.