Warren County
Also known as Warren County, Illinois, Warren County, IL
county in Illinois, United States
Key facts
- Country
- United States
- State
- Illinois
- Named after
- Joseph Warren
- Seat
- Monmouth
- Largest city
- Monmouth
- Total
- 543 sq mi (1,410 km )
- Land
- 542 sq mi (1,400 km )
- Water
- 0.6 sq mi (1.6 km ) 0.1%
- Estimate 2025
- 16,222
- Density
- 31.1/sq mi (12.0/km )
- Time zone
- UTC−6 ( Central )
- Summer dst
- UTC−5 ( CDT )
- Congressional districts
- 15th , 17th
Article
Warren County is a county in the U.S. state of Illinois. According to the 2020 census, it had a population of 16,835. Its county seat is Monmouth.
History