O'Fallon, Illinois
Area codes 618, 730 · Population: 28,281
Central (CT)
Illinois
Pop. 28,281
Area Codes Serving O'Fallon
About O'Fallon, Illinois
O'Fallon is a city in Illinois that is served by area codes 618, 730. The city has a population of approximately 28,281 residents and is located in the Central Time Zone.