331 Area Code Information
State: IL
Largest City in Area: AURORA
Where is Area Code 331? Area code (331) is in the state of IL. Below, are the major cities in the area code (331).
Major Cities in 331
- AURORA, IL (6,610)
- CHICAGO, IL (4,085)
- NAPERVILLE, IL (4,063)
- GENEVA, IL (1,533)
- BOLINGBROOK, IL (1,164)
- MONTGOMERY, IL (1,106)
- OSWEGO, IL (954)
- LISLE, IL (924)
- SAINT CHARLES, IL (867)
- DOWNERS GROVE, IL (846)
Zip Codes in 331