O Fallon, IL Area Codes
O Fallon is served by area codes 618 and 730. It is in Illinois, St. Clair County. About 35,923 people live in its 1 ZIP codes.
| Field | Value |
|---|---|
| Area code(s) | 618, 730 |
| State / province | Illinois |
| County | St. Clair County |
| Population | 35,923 |
| ZIP codes | 1 |
| Time zone | Central |
| Coordinates | 38.6000, -89.9154 |
What area code is O Fallon in?
ZIP codes in the code footprint
Nearby towns and their area codes
Fairview Heights 618, 730Collinsville 618, 730Troy 618, 730Belleville 618, 730Glen Carbon 618East Saint Louis 618, 730Mascoutah 618Granite City 618, 730
How to dial
Dial 618 + 7 digits for a number in O Fallon, or +1 618 ... from abroad. Ten-digit dialling is required everywhere in the North American Numbering Plan.