Marion County, Illinois
Marion County: county in Illinois, United States
About
Marion County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 39,437 and a population density of 27 people per km². After 10 years in 2020 county had an estimated population of 37,045 inhabitants. Its county seat is Salem. The county was created 203 years ago in 1822.
County Snapshot
Marion County at a glance
Marion County currently has 17 quality-checked populated place pages linked on MapSof, making it easier to jump from the county overview into local city pages.
Mapped populated places
17
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
CentraliaPopulation 12,142
Top linked places
Quick Facts about Marion County
| Population | 37,045 (2020) |
| Country | United States of America |
| State | Illinois (United States) |
| Different from | Marion County, Marion County, Marion County, Marion County, Marion County, Marion County, Marion County, Marion County, Marion County, Marion County, Marion County, Marion County, Marion County, Marion County, Marion County, Marion County |
| Area | 1481 km2 |
| Water as percent of area | 0.6% |
| Land as percent of area | 99.4% |
| Latitude & Longitude | 38.6496,-88.9190 |
| Named for | Francis Marion |
| Capital | Salem |
| Establishment | January 01, 1823 |
| Time Zone | America/Chicago |
| Local time | 23:59:45 (18th April 2026) |
| Density | 25 Pop. per km² as of 2020 |
| Population growth | -6.46% (2010-2020) |
| Weather | 62℉ Showers And Thunderstorms Likely 7-days weather |
Geography
Marion County is located at 38°38'59"N 88°55'8"W (38.6495900, -88.9189700). It has 6 neighbors: Clay County, Clinton County, Fayette County, Jefferson County, Washington County and Wayne County.
Marion County map
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The largest city of Marion County is Salem with a population of 6,952. Other cities include, Sandoval population 1,205, Wamac population 1,117, Central City population 1,107 and Odin population 1,004. See all Marion County cities & populated places.
Marion County Populated Places (more)
Cities, towns, neighborhoods & other populated places in Marion County.
| City Name | Population | Title |
|---|---|---|
| Centralia | 12,142 | Township in Marion County, Illinois |
| Salem | 6,952 | City in Illinois |
| Sandoval | 1,205 | Village in Marion County, Illinois, United States |
| Wamac | 1,117 | City in Marion County, Illinois, United States |
| Central City | 1,107 | City in Illinois, USA |
| Odin | 1,004 | Village in Illinois |
| Kinmundy | 919 | Township in Marion County, Illinois |
| Tonti | 903 | Township in Marion County, Illinois |
| Patoka | 544 | Township in Marion County, Illinois |
| Iuka | 495 | Township in Marion County, Illinois |
| Junction City | 468 | Human settlement in Illinois, United States of America |
| Omega | 466 | Township in Marion County, Illinois |
| Hickory Hill | 398 | City in Cook County, Illinois, United States |
| Alma | 302 | City in Illinois, USA |
| Kell | 204 | Human settlement in Illinois, United States of America |
| Vernon | 119 | Village in Illinois, United States |
Weather
Showers and thunderstorms likely before 4pm. Partly sunny. High near 62, with temperatures falling to around 57 in the afternoon. West wind 13 to 16 m...
7-Day Forecast- Salem
Demographics
According to census records, the population of Marion County decreased by 6.46% in 10 years.
| Year | Population | % Change | Method |
|---|---|---|---|
| 2010 | 39,437 | - | census |
| 2011 | 39,141 | -0.76% | estimation process |
| 2012 | 39,008 | -0.34% | estimation process |
| 2013 | 38,669 | -0.88% | estimation process |
| 2014 | 38,555 | -0.3% | estimation process |
| 2015 | 38,359 | -0.51% | estimation process |
| 2016 | 38,045 | -0.83% | estimation process |
| 2017 | 37,726 | -0.85% | estimation process |
| 2018 | 37,381 | -0.92% | estimation process |
| 2019 | 37,205 | -0.47% | estimation process |
| 2020 | 37,045 | -0.43% | estimation process |
People born in Marion County (3)
People born in Marion County, including United States federal judge Fred Louis Wham, Stephen French, judge Robert H. Loofbourrow, .
More notable people
Other places with the same name (16)
- Marion County, Indiana county in Oregon, United States with a population of 966,183 people.
- Marion County, Florida county in Florida, United States with a population of 373,513 people.
- Marion County, Oregon county in Oregon, United States with a population of 349,204 people.
- Marion County, Ohio county in Ohio, United States with a population of 64,820 people.
- Marion County, West Virginia county in West Virginia, United States with a population of 55,962 people.
- Marion County, Iowa county in Iowa, United States with a population of 33,168 people.
- Marion County, South Carolina county in South Carolina, United States with a population of 30,158 people.
- Marion County, Alabama county in Alabama, United States with a population of 29,703 people.
- Marion County, Tennessee county in Tennessee, United States with a population of 28,924 people.
- Marion County, Missouri county in northeast Missouri, United States with a population of 28,423 people.
- Marion County, Mississippi county in Mississippi, United States with a population of 24,441 people.
- Marion County, Kentucky county in Kentucky, United States with a population of 19,314 people.
- Marion County, Arkansas county in Arkansas, United States with a population of 16,790 people.
- Marion County, Kansas county in Kansas, United States with a population of 11,652 people.
- Marion County, Texas county in Texas, United States with a population of 9,960 people.
- Marion County, Georgia county in Georgia, United States with a population of 8,516 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. |