Johnson County | |
|---|---|
 Johnson County Courthouse in Vienna | |
 Location within the U.S. state of Illinois | |
 Illinois's location within the U.S. | |
| Coordinates: 37°28′N 88°52′W / 37.46°N 88.87°W | |
| Country |  United States |
| State |  Illinois |
| Founded | 1812 |
| Named for | 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 (2023) | 13,326  |
| • Density | 38/sq mi (15/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.[1] Its county seat is Vienna.[2] It is located in the southern portion of Illinois known locally as "Little Egypt".
- ^ "Johnson County, Illinois". United States Census Bureau. Retrieved June 9, 2023.
- ^ "Find a County". National Association of Counties. Archived from the original on May 9, 2015. Retrieved June 7, 2011.