COUNTY · KS
Johnson County, Kansas
Johnson County is a county in Kansas with FIPS code 20091 and an estimated population of 622,237 (Census 2023), 1st largest of 105 in the state.
County facts
- Name
- Johnson County
- State
- Kansas
- Type
- county
- FIPS code
- 20091
- State FIPS
- 20
- Population (2023)
- 622,237
- Change since 2020
- +1.8%
- State rank
- 1 of 105
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Johnson County?
Johnson County, Kansas has the five-digit FIPS code 20091: 20 for the state and 091 for the county.
What state is Johnson County in?
Johnson County is in Kansas.
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.