Warren County, Illinois
Warren County: county in Illinois, United States
About
Warren County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 17,707 and a population density of 33 people per km². After 10 years in 2020 county had an estimated population of 16,696 inhabitants. Its county seat is Monmouth. The county was created 201 years ago in 1824.
County Snapshot
Warren County at a glance
Warren County currently has 8 quality-checked populated place pages linked on MapSof, making it easier to jump from the county overview into local city pages.
Mapped populated places
8
These counts use a stricter populated-place filter so the main lists stay focused on real city and town pages.
Illinois counties
102
Open related pagesLargest city
MonmouthPopulation 8,801
Top linked places
Quick Facts about Warren County
| Population | 16,696 (2020) |
| Country | United States of America |
| State | Illinois (United States) |
| Different from | Warren County, Warren County, Warren County, Warren County, Warren County, Warren County, Warren County, Warren County, Warren County, Warren County, Warren County, Warren County, Warren County |
| Area | 543 km2 |
| Water as percent of area | 0.1% |
| Land as percent of area | 99.9% |
| Latitude & Longitude | 40.8488,-90.6150 |
| Named for | Joseph Warren |
| Capital | Monmouth |
| Establishment | January 01, 1825 |
| Time Zone | America/Chicago |
| Local time | 21:05:54 (18th April 2026) |
| Density | 31 Pop. per km² as of 2020 |
| Population growth | -6.06% (2010-2020) |
| Weather | 52℉ Rain Showers Likely 7-days weather |
Geography
Warren County is located at 40°50'56"N 90°36'54"W (40.8488300, -90.6150300). It has 5 neighbors: Fulton County, Henderson County, Knox County, McDonough County and Mercer County.
Warren County map
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The largest city of Warren County is Monmouth with a population of 8,801. Other cities include, Roseville population 885, Alexis population 778, Kirkwood population 670 and Little York population 304. See all Warren County cities & populated places.
Warren County Populated Places
Cities, towns, neighborhoods & other populated places in Warren County.
| City Name | Population | Title |
|---|---|---|
| Monmouth | 8,801 | City in Warren County, Illinois, United States |
| Roseville | 885 | Village in Illinois |
| Alexis | 778 | Village in Mercer and Warran counties in Illinois, United States |
| Kirkwood | 670 | Village in Warren County, Illinois, United States |
| Greenbush | 508 | Township in Warren County, Illinois |
| Coldbrook | 452 | Township in Warren County, Illinois, United States |
| Little York | 304 | Village in Warren County, Illinois, United States |
| Berwick | 300 | Unincorporated community in Illinois |
Weather
Rain showers likely before 1pm. Mostly sunny, with a high near 52. Chance of precipitation is 60%.
7-Day ForecastOfficial website of Warren County
Official WebsiteDemographics
According to census records, the population of Warren County decreased by 6.06% in 10 years.
| Year | Population | % Change | Method |
|---|---|---|---|
| 2010 | 17,707 | - | census |
| 2011 | 17,836 | 0.72% | estimation process |
| 2012 | 17,749 | -0.49% | estimation process |
| 2013 | 17,662 | -0.49% | estimation process |
| 2014 | 17,712 | 0.28% | estimation process |
| 2015 | 17,455 | -1.47% | estimation process |
| 2016 | 17,294 | -0.93% | estimation process |
| 2017 | 17,144 | -0.87% | estimation process |
| 2018 | 16,992 | -0.89% | estimation process |
| 2019 | 16,844 | -0.88% | estimation process |
| 2020 | 16,696 | -0.89% | estimation process |
People born in Warren County (5)
People born in Warren County, including football player and coach, athletic administrator, and lawyer Andrew G. Reid, anthropologist and archaeologist Edgar Lee Hewett, activist and journalist Lena Morrow Lewis, .
More notable people
- Charley Reynolds (American soldier) he was born in 01/01/1842
- Issac Grundy Davidson (American photographer) he was born in 01/01/1845
Other places with the same name (13)
- Warren County, Ohio county in New York, United States with a population of 238,412 people.
- Warren County, Kentucky county in Kentucky, United States with a population of 134,510 people.
- Warren County, New Jersey county in New Jersey, United States with a population of 105,624 people.
- Warren County, New York county in New York, United States with a population of 63,756 people.
- Warren County, Iowa county in Iowa, United States with a population of 52,265 people.
- Warren County, Mississippi county in Mississippi, United States with a population of 44,841 people.
- Warren County, Tennessee county in Tennessee, United States with a population of 41,605 people.
- Warren County, Virginia county in Virginia, United States with a population of 40,475 people.
- Warren County, Pennsylvania county in Pennsylvania, United States with a population of 38,911 people.
- Warren County, Missouri county in Missouri, United States with a population of 36,594 people.
- Warren County, North Carolina county in North Carolina, United States with a population of 19,522 people.
- Warren County, Indiana county in Indiana, United States with a population of 8,194 people.
- Warren County, Georgia county in Georgia, United States with a population of 5,232 people.
Illinois Other Counties (more counties)
| County Name | Population | Title |
|---|---|---|
| Cook County | 5,108,284 | County in Illinois, United States |
| Chicago | 2,677,643 | The third most populous city in the United States and the center of the Chicago metropolitan area. |
| DuPage County | 917,481 | County in Illinois, United States |
| Lake County | 693,593 | County in Oregon, United States |
| Will County | 688,726 | County in Illinois, United States |
| Kane County | 531,010 | County in southern Utah, United States |
| McHenry County | 305,888 | County in Illinois, United States |
| Winnebago County | 281,295 | County in Illinois, United States |
| Madison County | 262,635 | County in Montana, United States |
| Saint Clair County | 258,046 | The County of St. |
| Champaign County | 209,192 | County in Illinois, United States |
| Aurora | 196,383 | The second most populous city in Illinois. |
| Sangamon County | 193,882 | County in Illinois, United States |
| Peoria County | 177,652 | County in Illinois, United States of America |
| McLean County | 171,256 | County in North Dakota, United States |
| Naperville | 147,986 | The second most populous city in Illinois. |