Calhoun County, Illinois

Calhoun County
Location within the U.S. state of Illinois
Illinois's location within the U.S.
Coordinates: 39°10′N 90°40′W / 39.16°N 90.67°W / 39.16; -90.67
Country United States
State Illinois
Founded1825
Named afterJohn C. Calhoun
SeatHardin
Largest villageHardin
Area
  Total
284 sq mi (740 km2)
  Land254 sq mi (660 km2)
  Water30 sq mi (80 km2)  10.5%
Population
 (2020)
  Total
4,437
  Estimate 
(2023)
4,317
  Density16/sq mi (6.0/km2)
Time zoneUTC−6 (Central)
  Summer (DST)UTC−5 (CDT)
Congressional district15th
Websitewww.calhouncountyil.gov

Calhoun County is a county in the U.S. state of Illinois. As of the 2020 census, the population was 4,437, making it Illinois’ third-least populous county. Its county seat and biggest community is Hardin, with a population of 801. Its smallest incorporated community is Hamburg, with a population of 99. Calhoun County is at the tip of the peninsula formed by the courses of the Mississippi and Illinois rivers above their confluence and is almost completely surrounded by water. Calhoun County is sparsely populated; it has just five municipalities, all of them villages.

Calhoun County is part of the Metro-East portion of the St. Louis, MO-IL Metropolitan Statistical Area.