Warren County, Illinois

Warren County
County
Warren County Courthouse in Monmouth
Warren County Courthouse in Monmouth
Map of Illinois highlighting Warren County
Location within the U.S. state of Illinois
Map of the United States highlighting Illinois
Illinois's location within the U.S.
Coordinates: 40°51′N 90°37′W / 40.85°N 90.61°W / 40.85; -90.61
Country United States
State Illinois
Founded1825
Named forJoseph Warren
SeatMonmouth
Largest cityMonmouth
Area
 • Total543 sq mi (1,410 km2)
 • Land542 sq mi (1,400 km2)
 • Water0.6 sq mi (2 km2)  0.1%
Population
 (2020)
 • Total16,835
 • Density31/sq mi (12/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional districts15th, 17th
Websitewww.warrencountyil.com

Warren County is a county in the U.S. state of Illinois. According to the 2020 census, it had a population of 16,835.[1] Its county seat is Monmouth.[2]

  1. ^ "Warren County, Illinois". United States Census Bureau. Retrieved June 10, 2023.
  2. ^ "Find a County". National Association of Counties. Retrieved June 7, 2011.