McDonough County, Illinois
| McDonough County | |
|---|---|
| Location within the U.S. state of Illinois | |
| Illinois's location within the U.S. | |
| Coordinates: 40°28′N 90°41′W / 40.46°N 90.68°W | |
| Country | United States | 
| State | Illinois | 
| Founded | January 25, 1826 | 
| Named after | Thomas Macdonough | 
| Seat | Macomb | 
| Largest city | Macomb | 
| Area | |
|  • Total | 590 sq mi (1,500 km2) | 
| • Land | 589 sq mi (1,530 km2) | 
| • Water | 0.8 sq mi (2 km2) 0.1% | 
| Population  (2020) | |
|  • Total | 27,238 | 
| • Density | 46/sq mi (18/km2) | 
| Time zone | UTC−6 (Central) | 
| • Summer (DST) | UTC−5 (CDT) | 
| Congressional districts | 15th, 17th | 
| Website | mcg | 
McDonough County is a county in the U.S. state of Illinois. According to the 2020 census, it had a population of 27,238. Its county seat is Macomb, which is also the home of Western Illinois University.
McDonough County is part of the Macomb, IL Micropolitan Statistical Area.