COUNTY · WI
Waukesha County, Wisconsin
Waukesha County is a county in Wisconsin with FIPS code 55133 and an estimated population of 412,591 (Census 2023), 3rd largest of 72 in the state.
County facts
- Name
- Waukesha County
- State
- Wisconsin
- Type
- county
- FIPS code
- 55133
- State FIPS
- 55
- Population (2023)
- 412,591
- Change since 2020
- +1.3%
- State rank
- 3 of 72
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Waukesha County?
Waukesha County, Wisconsin has the five-digit FIPS code 55133: 55 for the state and 133 for the county.
What state is Waukesha County in?
Waukesha County is in Wisconsin.
How do I know if an address is in this county?
Use the address lookup. ZIP codes and city names can cross county lines, so an address is the reliable check.
Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27.