
Illiopolis
- County:
- Sangamon County
- County Seat:
- No
- Area (mi²):
- 0.677
- State:
- Illinois
Illiopolis is a village located in Sangamon County, Illinois. Illiopolis has a 2025 population of 822. Illiopolis is currently declining at a rate of -0.48% annually and its population has decreased by -2.61% since the most recent census, which recorded a population of 844 in 2020.
The average household income in Illiopolis is $77,651 with a poverty rate of 4.33%. The median age in Illiopolis is 45.5 years: 40 years for males, and 50.1 years for females.