U.S. PLACE PROFILE
O'Fallon, IL
O'Fallon is a City in St. Clair County, Illinois. The loaded 2025 population estimate is 32,656.
Published locationIllinois
Population estimate32,6562025 loaded Census estimate
CountySt. Clair CountyPrimary loaded county
Place typeCityCensus place classification
Coordinates38.60001, -89.91540Census representative point
EXPLORE FROM O'FALLON
Distance and nearby-place tools
Only tools with enough qualifying stored data are linked below.
Closest published places
Nearest qualifying Census places by straight-line distance.
Shiloh, IL3.3 miles · S
Fairview Heights, IL4.8 miles · W
Swansea, IL5.1 miles · SW
Lebanon, IL5.7 miles · E
Caseyville, IL6.7 miles · W
Belleville, IL7.1 miles · SW→County coverage
Some incorporated places cross county lines. These county-part values come from the loaded Census county-place-part population layer.
| County | 2025 population in this place part |
|---|---|
| St. Clair County | 32,656 |
DATA COVERAGE
What is available for O'Fallon
Geographic identityNearby placesPopulation estimate100-mile radius25-mile radius50-mile radius
PRIMARY GEOGRAPHIC SOURCE
U.S. Census Bureau
Place identity, coordinates and geographic identifiers are tied to the loaded Census source record for this location.