St. Clair County, Illinois cities by population
Number of cities: 37
Population: 258,597
Largest city: Belleville
| City | Type | Population |
|---|---|---|
| Belleville | city | 42,463 |
| O'Fallon | city | 31,963 |
| Collinsville | city | 24,627 |
| East St. Louis | city | 19,437 |
| Fairview Heights | city | 16,601 |
| Swansea | village | 15,037 |
| Shiloh | village | 13,638 |
| Cahokia | village | 12,440 |
| Columbia | city | 11,090 |
| Mascoutah | city | 8,803 |
| Lebanon | city | 4,737 |
| Centreville | city | 4,346 |
| Scott AFB | CDP | 4,219 |
| Freeburg | village | 4,195 |
| Smithton | village | 4,192 |
| Caseyville | village | 4,185 |
| Millstadt | village | 4,071 |
| Dupo | village | 4,001 |
| New Baden | village | 3,418 |
| Madison | city | 2,752 |
| Washington Park | village | 2,732 |
| Fairmont City | village | 2,176 |
| New Athens | village | 1,883 |
| Alorton | village | 1,864 |
| Marissa | village | 1,288 |
| St. Libory | village | 643 |
| Brooklyn | village | 627 |
| Hecker | village | 554 |
| Lenzburg | village | 423 |
| Fayetteville | village | 395 |
| Summerfield | village | 339 |
| East Carondelet | village | 276 |
| Sauget | village | 189 |
| Floraville | CDP | 31 |
| Paderborn | CDP | 26 |
| Darmstadt | CDP | 0 |
| Rentchler | CDP | 0 |
What is the largest city in St. Clair County, Illinois?
Belleville is the largest city in St. Clair County, Illinois with a population of 42,463.
TOP-5 cities by population in St. Clair County, Illinois:
- Belleville
- O'Fallon
- Collinsville
- East St. Louis
- Fairview Heights