Douglas County, Illinois
| Douglas County | |
|---|---|
| Douglas County Courthouse and veterans' memorial | |
| Location within the U.S. state of Illinois | |
| Illinois's location within the U.S. | |
| Coordinates: 39°46′N 88°13′W / 39.77°N 88.22°W | |
| Country | United States | 
| State | Illinois | 
| Founded | 1859 | 
| Named after | Stephen A. Douglas | 
| Seat | Tuscola | 
| Largest city | Tuscola | 
| Area | |
|  • Total | 417 sq mi (1,080 km2) | 
| • Land | 416 sq mi (1,080 km2) | 
| • Water | 0.6 sq mi (2 km2) 0.1% | 
| Population  (2020) | |
|  • Total | 19,740 | 
|  • Estimate  (2024) | 19,824 | 
| • Density | 47.7/sq mi (18.4/km2) | 
| Time zone | UTC−6 (Central) | 
| • Summer (DST) | UTC−5 (CDT) | 
| Congressional district | 15th | 
| Website | douglascountyil | 
Douglas County is a county located in the U.S. state of Illinois. As of the 2020 United States census, the population was 19,740. The county seat is Tuscola.