Johnson County, Illinois
Johnson County, Illinois | |
|---|---|
Johnson County Courthouse in Vienna | |
Location within the U.S. state of Illinois | |
| Coordinates: 37°28′N 88°52′W / 37.46°N 88.87°W | |
| Country | United States |
| State | Illinois |
| Founded | 1812 |
| Named after | Richard Mentor Johnson |
| Seat | Vienna |
| Largest city | Vienna |
| Area | |
• Total | 349 sq mi (900 km2) |
| • Land | 344 sq mi (890 km2) |
| • Water | 4.9 sq mi (13 km2) 1.4% |
| Population (2020) | |
• Total | 13,308 |
• Estimate (2024) | 13,320 |
| • Density | 38.7/sq mi (14.9/km2) |
| Time zone | UTC−6 (Central) |
| • Summer (DST) | UTC−5 (CDT) |
| Congressional district | 12th |
Johnson County is a county in the U.S. state of Illinois. According to the 2020 census, it has a population of 13,308. Its county seat is Vienna. It is located in the southern portion of Illinois known locally as "Little Egypt".