
Caseyville
- County:
- St. Clair County
- County Seat:
- No
- Area (mi²):
- 7.272
- State:
- Illinois
Caseyville is a village located in St. Clair County, Illinois. Caseyville has a 2025 population of 4,337. Caseyville is currently declining at a rate of -0.25% annually and its population has decreased by -1.23% since the most recent census, which recorded a population of 4,391 in 2020.
The average household income in Caseyville is $70,590 with a poverty rate of 17.9%. The median age in Caseyville is 42.7 years: 43.1 years for males, and 42.4 years for females.