Ottawa, Illinois
Central Time Zone (UTC-6) · IL · —
About Area Codes in Ottawa, Illinois
Ottawa, Illinois is served by 2 area codes: 815, 779. When multiple area codes serve the same geographic area, it typically indicates overlay codes have been added to accommodate growing demand for phone numbers. All local calls within Ottawa require 10-digit dialing. The city is in the Central time zone (UTC-6).
Other cities in area code 815
Frequently Asked Questions
What area code is Ottawa, Illinois?
Ottawa, Illinois uses area codes 815 and 779.
What time zone is Ottawa in?
Ottawa is in the Central time zone (UTC-6).
Do I need to dial 10 digits when calling Ottawa?
Yes, all local calls in Ottawa require 10-digit dialing because the area is served by multiple overlay area codes.
When was area code 815 created?
Area code 815 is one of the original 86 area codes established in 1947 as part of the North American Numbering Plan (NANP).
What cities share area code 815 with Ottawa?
Other cities sharing area code 815 with Ottawa include Belvidere, Bolingbrook, Channahon, Crystal Lake, DeKalb, among others.
Ottawa, IL · Central Time Zone