COUNTY · KS
Jefferson County, Kansas
Jefferson County is a county in Kansas with FIPS code 20087 and an estimated population of 18,327 (Census 2023), 30th largest of 105 in the state.
County facts
- Name
- Jefferson County
- State
- Kansas
- Type
- county
- FIPS code
- 20087
- State FIPS
- 20
- Population (2023)
- 18,327
- Change since 2020
- +0.0%
- State rank
- 30 of 105
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Jefferson County?
Jefferson County, Kansas has the five-digit FIPS code 20087: 20 for the state and 087 for the county.
What state is Jefferson County in?
Jefferson 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.