
Effingham
- County:
- Effingham County
- County Seat:
- Yes
- Area (mi²):
- 10.703
- State:
- Illinois
Effingham is a city located in Effingham County, Illinois. Effingham has a 2025 population of 12,233. It is also the county seat of Effingham County. Effingham is currently declining at a rate of -0.1% annually and its population has decreased by -0.5% since the most recent census, which recorded a population of 12,295 in 2020.
The average household income in Effingham is $80,235 with a poverty rate of 14.82%. The median age in Effingham is 36.9 years: 37.2 years for males, and 36.8 years for females.