Waukesha County
Also known as Waukesha County, Wisconsin, Waukesha County, WI
county in Wisconsin, United States
Key facts
- Country
- United States
- State
- Wisconsin
- County seat
- Waukesha
- Largest city
- Waukesha
- Total
- 581 sq mi (1,500 km )
- Land
- 550 sq mi (1,400 km )
- Water
- 31 sq mi (80 km )
- Estimate 2025
- 417,210
- Rank
- 3rd largest county in Wisconsin
- Density
- 740/sq mi (290/km )
- Time zone
- UTC−6 ( Central )
- Summer dst
- UTC−5 ( Central )
- Area codes
Article
Waukesha County sign on WIS 59
Waukesha County (/ˈwɔːkɪʃɔː/ ) is a county in the U.S. state of Wisconsin. As of the 2020 United States Census, the population was 406,978, making it the third-most populous county in Wisconsin. Its median income of $88,985 placed it as the only county in Wisconsin on the list of the 100 highest-income counties in the U.S. by median income as of 2020. Its county seat and largest city is Waukesha.