Johnson County, Illinois

Johnson County
Johnson County Courthouse in Vienna
Map of Illinois highlighting Johnson County
Location within the U.S. state of Illinois
Map of the United States highlighting Illinois
Illinois's location within the U.S.
Coordinates: 37°28′N 88°52′W / 37.46°N 88.87°W / 37.46; -88.87
Country United States
State Illinois
Founded1812
Named forRichard Mentor Johnson
SeatVienna
Largest cityVienna
Area
 • Total349 sq mi (900 km2)
 • Land344 sq mi (890 km2)
 • Water4.9 sq mi (13 km2)  1.4%
Population
 (2020)
 • Total13,308
 • Estimate 
(2023)
13,326 Increase
 • Density38/sq mi (15/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional district12th

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".

  1. ^ "Johnson County, Illinois". United States Census Bureau. Retrieved June 9, 2023.
  2. ^ "Find a County". National Association of Counties. Archived from the original on May 9, 2015. Retrieved June 7, 2011.