Joliet, Illinois
Area codes 331, 630, 779, 815 · Population: 147,433
Central (CT)
Illinois
Pop. 147,433
Area Codes Serving Joliet
About Joliet, Illinois
Joliet is a city in Illinois that is served by area codes 331, 630, 779, 815. The city has a population of approximately 147,433 residents and is located in the Central Time Zone.