Williamson County, Illinois
Williamson County, Illinois | |
|---|---|
Williamson County Courthouse in Marion | |
Location within the U.S. state of Illinois | |
| Coordinates: 37°44′N 88°56′W / 37.73°N 88.93°W | |
| Country | United States |
| State | Illinois |
| Founded | February 28, 1839 |
| Named after | Williamson County, Tennessee |
| Seat | Marion |
| Largest city | Marion |
| Area | |
• Total | 444 sq mi (1,150 km2) |
| • Land | 420 sq mi (1,100 km2) |
| • Water | 24 sq mi (62 km2) 5.4% |
| Population (2020) | |
• Total | 67,153 |
• Estimate (2024) | 67,064 |
| • Density | 160/sq mi (62/km2) |
| Time zone | UTC−6 (Central) |
| • Summer (DST) | UTC−5 (CDT) |
| Congressional district | 12th |
| Website | www |
Williamson County is a county in Illinois. At the 2020 census, it had a population of 67,153. Its largest city and county seat is Marion. Williamson County is part of the Metro Lakeland area of Southern Illinois.