Clay County, Illinois

Clay County
Location within the U.S. state of Illinois
Illinois's location within the U.S.
Coordinates: 38°46′N 88°29′W / 38.76°N 88.49°W / 38.76; -88.49
Country United States
State Illinois
FoundedDecember 23, 1824 (created)
March 8, 1825 (organized)
Named afterHenry Clay
SeatLouisville
Largest cityFlora
Area
  Total
469.59 sq mi (1,216.2 km2)
  Land468.32 sq mi (1,212.9 km2)
  Water1.28 sq mi (3.3 km2)  0.3%
Population
 (2020)
  Total
13,288
  Estimate 
(2023)
12,999
  Density28/sq mi (11/km2)
Time zoneUTC−6 (Central)
  Summer (DST)UTC−5 (CDT)
Congressional district12th
Websiteclaycountyillinois.org

Clay County is a county in the southeastern portion of the U.S. state of Illinois. As of the 2020 United States census, the population was 13,288. Since 1842, its county seat has been Louisville, in the center of the county's area. In 1950, the U.S. Census Bureau placed the mean center of U.S. population in Clay County.