COUNTY · IL
Piatt County, Illinois
Piatt County is a county in Illinois with FIPS code 17147 and an estimated population of 16,714 (Census 2023), 61st largest of 102 in the state.
County facts
- Name
- Piatt County
- State
- Illinois
- Type
- county
- FIPS code
- 17147
- State FIPS
- 17
- Population (2023)
- 16,714
- Change since 2020
- +0.2%
- State rank
- 61 of 102
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Piatt County?
Piatt County, Illinois has the five-digit FIPS code 17147: 17 for the state and 147 for the county.
What state is Piatt County in?
Piatt County is in Illinois.
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.