Washington County, Illinois
Washington County: county in Illinois, United States.
About
Washington County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 14,716 and a population density of 10 people per km². After 10 years in 2020 county had an estimated population of 13,764 inhabitants. Its county seat is Nashville. The county was created 208 years ago in 1817.
County Snapshot
Washington County at a glance
Washington County currently has 2 quality-checked populated place pages linked on MapSof, making it easier to jump from the county overview into local city pages.
Mapped populated places
2
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
PosenPopulation 5,794
Top linked places
Quick Facts about Washington County
| Population | 13,764 (2020) |
| Country | United States of America |
| State | Illinois (United States) |
| Different from | Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County, Washington Parish, Washington County, Washington County, Washington County, Washington County, Washington County, Washington County |
| Area | 1461 km2 |
| Water as percent of area | 0.2% |
| Land as percent of area | 99.8% |
| Latitude & Longitude | 38.3522,-89.4105 |
| Named for | George Washington |
| Capital | Nashville |
| Establishment | January 01, 1818 |
| Time Zone | America/Chicago |
| Local time | 05:31:07 (23rd September 2026) |
| Density | 9 Pop. per km² as of 2020 |
| Population growth | -6.47% (2010-2020) |
| Weather | 74℉ Mostly Sunny 7-days weather |
Geography
Washington County is located at 38°21'8"N 89°24'38"W (38.3521700, -89.4104500). It has 6 neighbors: Clinton County, Jefferson County, Marion County, Perry County, Randolph County and Saint Clair County.
Washington County map
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The largest city of Washington County is Posen with a population of 5,794. Other cities include and Nashville population 2,984. See all Washington County cities & populated places.
Washington County Populated Places
Cities, towns, neighborhoods & other populated places in Washington County.
| City Name | Population | Title |
|---|---|---|
| Posen | 5,794 | Village in United States of America |
| Nashville | 2,984 | City in Illinois, United States |
Official website of Washington County
Official WebsiteDemographics
According to census records, the population of Washington County decreased by 6.47% in 10 years.
| Year | Population | % Change | Method |
|---|---|---|---|
| 2010 | 14,716 | - | census |
| 2011 | 14,576 | -0.95% | estimation process |
| 2012 | 14,599 | 0.16% | estimation process |
| 2013 | 14,414 | -1.27% | estimation process |
| 2014 | 14,392 | -0.15% | estimation process |
| 2015 | 14,262 | -0.9% | estimation process |
| 2016 | 14,179 | -0.58% | estimation process |
| 2017 | 13,963 | -1.52% | estimation process |
| 2018 | 13,999 | 0.26% | estimation process |
| 2019 | 13,887 | -0.8% | estimation process |
| 2020 | 13,764 | -0.89% | estimation process |
People born in Washington County (2)
People born in Washington County, including judge: justice on the Illinois Supreme Court Lloyd A. Karmeier, Illinois politician Charles Meier, .
More notable people
Other places with the same name (29)
- Washington County, Oregon county in Oregon, United States. with a population of 603,514 people.
- Washington County, Minnesota county in Minnesota, United States. with a population of 265,476 people.
- Washington County, Arkansas county in Arkansas, United States. with a population of 243,216 people.
- Washington County, Pennsylvania county in Pennsylvania, United States. with a population of 206,803 people.
- Washington County, Utah county in southwestern Utah, United States. with a population of 184,913 people.
- Washington County, Maryland county in Maryland, United States. with a population of 151,146 people.
- Washington County, Wisconsin county in Wisconsin, United States. with a population of 136,445 people.
- Washington County, Tennessee county in Tennessee, United States. with a population of 130,367 people.
- Washington County, Rhode Island county in Rhode Island, United States. with a population of 125,746 people.
- Washington County, New York county in New York, United States. with a population of 60,606 people.
- Washington County, Ohio county in Ohio, United States. with a population of 59,652 people.
- Washington County, Vermont county in Vermont, United States. with a population of 58,328 people.
- Washington County, Virginia county in Virginia, United States. with a population of 53,695 people.
- Washington County, Oklahoma county in Oklahoma, United States. with a population of 52,222 people.
- Washington County, Mississippi county in Mississippi, United States. with a population of 42,837 people.
- Washington County, Texas county in Texas, United States. with a population of 35,771 people.
- Washington County, Maine county in Maine, United States. with a population of 31,473 people.
- Washington County, Indiana county in Indiana, United States. with a population of 28,213 people.
- Washington County, Florida county in Florida, United States. with a population of 25,932 people.
- Washington County, Missouri county in Missouri, United States. with a population of 24,604 people.
- Washington County, Iowa county in Iowa, United States. with a population of 21,992 people.
- Washington County, Nebraska county in Nebraska, United States. with a population of 20,901 people.
- Washington County, Georgia county in Georgia, United States. with a population of 20,150 people.
- Washington County, Alabama county in Alabama, United States. with a population of 15,976 people.
- Washington County, Kentucky county in Kentucky, United States. with a population of 12,147 people.
- Washington County, North Carolina county in North Carolina, United States. with a population of 11,485 people.
- Washington County, Idaho county in Idaho, United States. with a population of 10,194 people.
- Washington County, Kansas county in Kansas, United States. with a population of 5,427 people.
- Washington County, Colorado county in Colorado, United States. with a population of 4,875 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. |