Saint Clair County , Illinois

Saint Clair County: The County of St. Clair is the oldest county in the U. S. Illinois state; the Mississippi River, bordering the U, forms its western boundary. S. Missouri State. In southern Illinois, it is part of the Metro East. It had a population of 270,056 according to the 2010 United States Census, making it the eighth-most populous county in Illinois and the most populous in the state's southern part. Its seat in the county is Belleville.

Saint Clair County locator map
Location of Saint Clair County on Illinois map.

About

Saint Clair County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 270,056 and a population density of 155 people per km². After 9 years in 2019 county had an estimated population of 259,686 inhabitants. Its county seat is Belleville. The county was created 231 years ago in 1790.

Geography

Saint Clair County is located at 38°28'13"N 89°55'42"W (38.4703100, -89.9284100). It has 2 neighbors: Monroe County and Randolph County.

Downtown Belleville Illinois Courthouse image
Downtown Belleville Illinois Courthouse

The largest city of Saint Clair County is Belleville with a population of 40,897. Other cities include, East Saint Louis population 26,047, Crest Hill population 20,376, Fairview Heights population 16,303 and Pontiac population 11,253. See all Saint Clair County cities & populated places.

Downtown Belleville Illinois Courthouse image

Saint Clair County map

Saint Clair County Quick Facts

Population : 259,686 (2019)
Country : United States of America
State : Illinois (United States)
Different from : St. Clair County, St. Clair County, St. Clair County
Area : 1746 km2
Water as percent of area : 2.4%
Land as percent of area : 97.6%
Named for : Arthur St. Clair
Capital : Belleville
Establishment : April 04, 1790
Time Zone : America/Chicago
Local time : 21:18:05 (4th August 2021)
Density : 149 Pop. per km² as of 2019
Population growth : -3.99% (2010-2019)

Saint Clair County has 2 neighbours.

Demographics

According to census records, the population of Saint Clair County decreased by 3.99% in 9 years.

Year Population % Change Method
2010 270,056 - census
2011 270,048 -0% estimation process
2012 268,673 -0.51% estimation process
2013 266,831 -0.69% estimation process
2014 265,941 -0.33% estimation process
2015 264,858 -0.41% estimation process
2016 263,187 -0.63% estimation process
2017 262,600 -0.22% estimation process
2018 261,360 -0.47% estimation process
2019 259,686 -0.64% estimation process

Comte de Saint Clair, Comté de Saint Clair, Saint Clair

People born in Saint Clair County (4)

People born in Saint Clair County, including baseball player Neal Cotts, artist Paul Soldner, politician Charles A. Karch, you can see a list of people who born in Saint Clair County.

Other places with the same name (3)

Saint Clair County Populated Places (more)

Cities, Towns, Neighborhoods & Other Populated Places in Saint Clair County.

City Name Population Title
Glenview 47,308 Village in Cook County, Illinois, United States
Belleville 40,897 City in Illinois
O'Fallon 26,540 Township in St.
East Saint Louis 26,047 City in St.
Crest Hill 20,376 City in Will County, Illinois
Fairview Heights 16,303 City in Saint Clair County, Illinois, United States
Cahokia 13,880 Village in St.
Shiloh 13,586 Town in St.
Swansea 13,350 Village in St.
Pontiac 11,253 City in Illinois, USA
Summit 11,116 Village in Illinois, USA
Mascoutah 8,653 City in Saint Clair County, Illinois, United States
Centreville 4,897 City in Illinois, United States
Lebanon 4,265 City in St.
Freeburg 4,242 City in Illinois, United States of America
Caseyville 4,110 City in Illinois, United States of America

Illinois Other Counties (more counties)

County Name Population Title
Illinois 12,671,821 State of the United States of America
Cook County 5,150,233 County in Illinois, United States
Chicago 2,693,976 City and county seat of Cook County, Illinois, United States
DuPage County 922,921 County in Illinois, United States
Lake County 696,535 County in Oregon, United States
Will County 690,743 County in Illinois, United States
Kane County 532,403 County in southern Utah, United States
Markham 328,966 City in Cook County, Illinois, United States
McHenry County 307,774 County in Illinois, United States
Winnebago County 282,572 County in Illinois, United States
Madison County 262,966 County in Montana, United States
Champaign County 209,689 County in Illinois, United States
Sangamon County 194,672 County in Illinois, United States
Peoria County 179,179 County in Illinois, United States of America
McLean County 171,517 County in North Dakota, United States
Rockford 169,980 County seat of Winnebago County, Illinois, United States

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