Southwest Illinois Cities

City
Rank
County
2026 Pop. ↓
Belleville1St. Clair County39,809
O'Fallon2St. Clair County32,600
Granite City3Madison County26,659
Edwardsville4Madison County26,384
Alton5Madison County24,865
Collinsville6Madison County23,578
Godfrey7Madison County17,577
East St. Louis8St. Clair County17,559
Cahokia Heights9St. Clair County16,678
Fairview Heights10St. Clair County16,038
Shiloh11St. Clair County14,743
Swansea12St. Clair County14,382
Glen Carbon13Madison County13,907
Troy14Madison County11,986
Waterloo15Monroe County11,182
Columbia16Monroe County10,845
Wood River17Madison County10,184
Highland18Madison County10,034
Mascoutah19St. Clair County9,322
Bethalto20Madison County9,176
Maryville21Madison County8,438
Jerseyville22Jersey County8,414
Greenville23Bond County7,442
Chester24Randolph County6,829
Pontoon Beach25Madison County5,887
East Alton26Madison County5,589
Lebanon27St. Clair County4,879
Breese28Clinton County4,589
Freeburg29St. Clair County4,487
Caseyville30St. Clair County4,405
Scott AFB31St. Clair County4,330
Rosewood Heights32Madison County4,049
Sparta33Randolph County4,009
Millstadt34St. Clair County3,921
Smithton35St. Clair County3,840
Red Bud36Randolph County3,754
Dupo37St. Clair County3,721
New Baden38Clinton County3,368
Holiday Shores39Madison County3,227
Carlyle40Clinton County3,177
Madison41Madison County3,045
Nashville42Washington County2,992
Trenton43Clinton County2,635
Aviston44Clinton County2,473
Washington Park45Madison County2,435
Fairmont City46Madison County2,132
Steeleville47Randolph County1,876
South Roxana48Madison County1,839
New Athens49St. Clair County1,834
Marissa50St. Clair County1,702
Venice51Madison County1,441
Germantown52Clinton County1,391
Roxana53Madison County1,386
St. Jacob54Madison County1,370
Okawville55Washington County1,338
Valmeyer56Monroe County1,201
Hartford57Madison County1,146
Albers58Clinton County1,111
Worden59Madison County1,060
Central City60Clinton County1,059
Marine61Madison County982
Wamac62Clinton County956
Hamel63Madison County936
Beckemeyer64Clinton County921
Percy65Randolph County904
Coulterville66Randolph County824
Grafton67Jersey County804
Hardin68Calhoun County775
Tilden69Randolph County745
Livingston70Madison County744
Mitchell71Madison County730
Pocahontas72Bond County663
Bartelso73Clinton County646
Brooklyn74St. Clair County620
Alhambra75Madison County610
St. Libory76St. Clair County592
Irvington77Washington County562
Damiansville78Clinton County559
Elsah79Jersey County537
Evansville80Randolph County531
Junction City81Clinton County514
Prairie du Rocher82Monroe County513
Hoyleton83Washington County498
Mulberry Grove84Bond County493
St. Rose85Clinton County472
Ashley86Washington County446
Pierron87Bond County438
Lenzburg88St. Clair County431
Hoffman89Clinton County429
Hecker90Monroe County416
Moro91Madison County415
Sorento92Bond County406
Keyesport93Clinton County403
East Carondelet94St. Clair County366
Medora95Jersey County363
New Douglas96Madison County337
Summerfield97St. Clair County332
Grantfork98Bond County329
Ellis Grove99Randolph County324
Baldwin100Randolph County312
Ruma101Monroe County312
Kampsville102Calhoun County292
Fayetteville103St. Clair County283
Addieville104Washington County255
Richview105Washington County231
Oakdale106Washington County197
Radom107Washington County183
Du Bois108Washington County179
Batchtown109Calhoun County165
Huey110Clinton County159
Fieldon111Jersey County157
Maeystown112Monroe County150
Smithboro113Bond County147
Sauget114Madison County128
Venedy115Washington County124
Brussels116Calhoun County110
Fidelity117Jersey County95
Hamburg118Calhoun County94
Old Ripley119Bond County84
Rockwood120Randolph County31
Fults121Monroe County26
Kaskaskia122Randolph County22

About Southwest Illinois

Madison County, St. Clair County, Clinton County, Monroe County, Randolph County, Jersey County, Bond County, Washington County, and Calhoun County are the counties generally considered part of Southwest Illinois.

Sources

  1. US Census: 2025 Gazetteer Files
  2. City and Town Population Totals: 2020-2024