O'Fallon, Illinois
O'Fallon is a city in St. Clair County, Illinois, with an estimated population of 31,968 in 2023. It sits at 38.6000, -89.9154 in the America/Chicago time zone.
| Field | Value |
|---|---|
| Place name | O'Fallon |
| Type | city |
| State | Illinois (IL) |
| County | St. Clair County |
| Population (2023 est.) | 31,968 |
| Land area | 15.79 sq mi (40.90 km²) |
| Coordinates | 38.6000, -89.9154 |
| Time zone | America/Chicago |
| Telephone area codes | 618 |
Where is O'Fallon?
O'Fallon is located in Illinois, in St. Clair County. The coordinates above can be pasted directly into any map service. The nearest indexed places are listed below, which is a useful check when two states share a place name.
Nearby places
Shiloh 5 km · ILFairview Heights 8 km · ILSwansea 8 km · ILLebanon 9 km · ILCaseyville 11 km · ILBelleville 11 km · ILCollinsville 12 km · ILMascoutah 14 km · IL
Other places in St. Clair County
Belleville 40,726East St. Louis 17,642Cahokia Heights 17,114Fairview Heights 16,125Shiloh 14,736Swansea 14,472Mascoutah 8,916Lebanon 4,571Freeburg 4,501Caseyville 4,359
Frequently asked questions
What county is O'Fallon, IL in?
O'Fallon is in St. Clair County, Illinois.
What is the population of O'Fallon, IL?
The 2023 Census Bureau estimate is 31,968.
What time zone is O'Fallon in?
O'Fallon is in the America/Chicago time zone.