
Sangamon County
- State:
- Illinois
- County Seat:
- Springfield
Sangamon County's estimated 2025 population is 192,171 with a growth rate of -0.34% in the past year according to the most recent United States census data. Sangamon County is the 11th largest county in Illinois. The 2010 population was 197,769 and has seen a growth of -2.83% since that time.