O'Fallon Map
The City of O'Fallon is located in St. Clair County in the State of Illinois. Find directions to O'Fallon, browse local businesses, landmarks, get current traffic estimates, road conditions, and more. According to the 2019 US Census the O'Fallon population is estimated at 29,606 people. The O'Fallon time zone is Central Daylight Time which is 6 hours behind Coordinated Universal Time (UTC).
Nearby cities include Petersburg, Glenview, Carbon, Washington Park, Canteen.