
Shelby County
- State:
- Illinois
- County Seat:
- Shelbyville
Shelby County's estimated 2025 population is 20,284 with a growth rate of -0.7% in the past year according to the most recent United States census data. Shelby County is the 57th largest county in Illinois. The 2010 population was 22,354 and has seen a growth of -9.26% since that time.