
Madison County
- State:
- Illinois
- County Seat:
- Edwardsville
Madison County's estimated 2025 population is 261,112 with a growth rate of -0.31% in the past year according to the most recent United States census data. Madison County is the 8th largest county in Illinois. The 2010 population was 269,315 and has seen a growth of -3.05% since that time.