O Fallon, Illinois Area Code
O Fallon, IL is officially utilizing two area codes which are area codes 618 and 730.
In addition to O Fallon, IL area code information read more about area code 618 details, area code 730 details, and Illinois area codes.
O Fallon, IL is located in Saint Clair County and observes the Central Time Zone.
View our Times by Area Code tool.
Area Codes Look Up By State and City
Area Codes Look Up in Surrounding Places
