Waukesha County, Wisconsin

Waukesha County is a county in Wisconsin, United States, about 15 miles west of Milwaukee. It had a population of 406,978 at the 2020 census, an estimated 417,210 by 2024, and covers 581 square miles (1,500 km2) centred near 43°01′N 88°19′W.

Waukesha is the county seat and largest city; its postal code is 53186. The county holds 7 cities, 22 incorporated villages and 8 towns — a Wisconsin town is a full municipal government, not a survey township — plus one census-designated place, and it runs on Central Time. Its FIPS code is 55133.

Towns & Villages in Waukesha County

Waukesha County has 38 named places on record: 7 cities (one the county seat), 22 incorporated villages, 8 towns and one census-designated place (CDP). In Wisconsin a town is an incorporated municipal government in its own right, not a geographic subdivision as in most Midwestern states, and several towns kept their name after part of their territory broke away and incorporated separately as a city or village.

Six names appear twice on this list. Brookfield, Delafield, Eagle, Merton, Mukwonago and Oconomowoc each have both an incorporated city or village and a separate town government sharing the same name — the town is what remains of the original 1840s township after part of it split off and incorporated. Their population figures are counted separately; a resident of the Town of Oconomowoc is not also a resident of the City of Oconomowoc. In January 2025 most of the Town of Oconomowoc, plus the unincorporated Okauchee Lake community, was annexed into the neighboring Village of Lac La Belle, shrinking the town to a small remaining sliver — its 8,836 figure above is the pre-annexation 2020 count, and Lac La Belle’s 281 is likewise its last count before the annexation took effect.

ZIP Codes

• 53186 — Waukesha (also serves 53187–53189, Waukesha post office box ZIPs)
• 53005 — Brookfield (the city also uses 53045 and 53072)
• 53146 — New Berlin (also serves 53151)
• 53051 — Menomonee Falls (also serves 53052)
• 53150 — Muskego
• 53066 — Oconomowoc and the Village of Summit (Oconomowoc also uses 53067)
• 53072 — City of Pewaukee (a postal zone shared with part of Brookfield)
• 53089 — Sussex
• 53029 — Hartland and the Village of Merton
• 53149 — Mukwonago
• 53018 — City of Delafield
• 53183 — Wales
• 53118 — Dousman
• 53159 — North Prairie
• 53119 — Eagle
• 53103 — Big Bend
• 53046 — Lannon
• 53068 — Oconomowoc Lake
• 53064 — North Lake

Lisbon, the Village of Waukesha, the Village of Pewaukee, Elm Grove, Butler, Nashotah, Chenequa and Lac La Belle have no ZIP code of their own; mail there is delivered under a neighboring incorporated place’s code. None of the county’s eight towns runs its own post office either — each uses the ZIP of the city or village nearest its town hall.

Geography

Waukesha County sits in southeastern Wisconsin’s Kettle Moraine region, glacially carved terrain of moraines, kettles and more than 100 lakes that gives the county its “Lake Country” nickname. Of its 581 square miles, 550 are land and 31 are water, about 5.3 percent — unusually high for the state, concentrated around Pewaukee Lake, Oconomowoc Lake, Beaver Lake, Nagawicka Lake and North Lake. The Fox River rises in the county’s southern half, and the Bark River crosses its western towns; both eventually drain into the Mississippi River by way of the Illinois and Rock rivers.

Washington County lies to the north, Ozaukee County to the northeast, Milwaukee County to the east, Racine County to the southeast, Walworth County to the southwest, Jefferson County to the west and Dodge County to the northwest. Washington County, Ozaukee County, Milwaukee County, Racine County, Walworth County, Jefferson County and Dodge County all border Waukesha directly.

Demographics

Waukesha County had a population of 406,978 at the 2020 census, and a 2024 Census Bureau estimate put it near 417,210 — Wisconsin’s third-most-populous county, behind Milwaukee and Dane. Waukesha and Brookfield are its two largest communities, together home to more than a quarter of the county’s residents. Median household income runs $88,985 (2020 American Community Survey), well above Wisconsin’s statewide $74,631 (2023 ACS); the county is the only one in Wisconsin that ranks among the nation’s 100 highest-income counties. Population density works out to roughly 740 people per square mile of land, among the densest in the state outside Milwaukee County itself.

Economy & Local Life

Health care, manufacturing and retail trade employ the most workers in the county. GE Healthcare’s ultrasound and imaging plant in Waukesha is among the county’s largest single employers, with about 2,477 workers as of 2017, followed by Waukesha Memorial Hospital (2,149) and the Waukesha School District (1,800). Generac Power Systems, maker of home standby generators, and Cooper Power Systems (1,006) both run major operations from the city. Kohl’s, the department-store chain, is headquartered in Menomonee Falls and employed about 4,000 people there as of 2022, alongside Froedtert Health (3,000) and Briggs & Stratton (1,300). New Berlin’s industrial parks host ABB Industrial Systems, ACS Group and Ideal Mechanical. Quad/Graphics, one of the country’s largest commercial printers, is headquartered in Sussex. Old World Wisconsin, an open-air museum recreating 19th-century immigrant farmsteads, operates in the Town of Eagle and draws visitors from across the Midwest.

History

The Wisconsin Territorial Legislature split Waukesha County off from Milwaukee County in January 1846, two years before statehood; Curtis Reed served as its first county chairman. Voters chose Waukesha over Pewaukee as county seat by a margin of just two votes. The name comes from the Potawatomi word for “fox,” after the streams draining the county’s lower half into the Fox River.

Waukesha built a national reputation in the late 1800s as a health-spa destination. Colonel Richard Dunbar discovered the Bethesda Spring in 1868 and promoted its water as a cure for diabetes; by the 1870s the city, nicknamed “Spring City” and the “Saratoga of the West,” drew hundreds of visitors a year, and a cluster of bottling companies shipped Waukesha spring water nationwide. An 1890s scheme to pipe the water to Chicago for the 1893 World’s Fair collapsed for lack of funding. Sears, Roebuck and Co. founder Richard Warren Sears retired to Waukesha for the water’s reputed benefits and died there in 1914. Pollution and over-pumping eventually dried up or closed most of the springs, and the county’s economy shifted toward manufacturing and, later, health care.

Getting There

Interstate 94 crosses the county’s northeast corner through New Berlin and Brookfield, and Interstate 43 runs along the eastern edge past Brookfield and Menomonee Falls. US 18, US 41 and US 45 also cross the county, along with Wisconsin highways 16, 36, 59, 67, 83, 100, 145, 164, 175 and 190.

• Milwaukee — about 15 miles east
• Madison — about 60 miles west
• Racine — about 20 miles southeast
• Fond du Lac — about 35 miles north

Milwaukee Mitchell International Airport, about 20 miles southeast of Waukesha, is the nearest major commercial airport. Waukesha County Airport, on the city’s north side, handles general aviation and charter traffic. Amtrak’s Hiawatha and Empire Builder trains stop at Milwaukee’s downtown Intermodal Station; Waukesha County itself has no passenger rail station.

Frequently Asked Questions

Where is Waukesha County located?
It sits in southeastern Wisconsin’s Lake Country, about 15 miles west of Milwaukee, bordered by Washington, Ozaukee, Milwaukee, Racine, Walworth, Jefferson and Dodge counties.

What is the population of Waukesha County?
406,978 at the 2020 census, with a 2024 estimate near 417,210.

How big is Waukesha County?
581 square miles (1,500 km2), of which 550 square miles are land and 31 square miles are water.

What is the county seat of Waukesha County?
Waukesha, chosen over Pewaukee by a two-vote margin when the county organized in 1846.

How many towns, villages and cities are in Waukesha County?
Seven cities, 22 incorporated villages and 8 towns, plus the North Lake census-designated place — 38 named places in all.

What ZIP codes does Waukesha County use?
53186 for Waukesha, 53005 for Brookfield, 53146 for New Berlin, 53051 for Menomonee Falls, 53150 for Muskego, 53066 for Oconomowoc, and separate codes for most of the county’s smaller villages.

What is Waukesha County known for?
Manufacturing and health care employers such as GE Healthcare and Generac Power Systems today, and its 19th-century run as “Spring City,” a mineral-water spa resort that once shipped bottled water nationwide.

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