
Mason
- County:
- Effingham County
- County Seat:
- No
- Area (mi²):
- 1.287
- State:
- Illinois
Mason is a town located in Effingham County, Illinois. Mason has a 2025 population of 315. Mason is currently declining at a rate of -0.63% annually and its population has decreased by -3.08% since the most recent census, which recorded a population of 325 in 2020.
The average household income in Mason is $64,997 with a poverty rate of 24.11%. The median age in Mason is 36.9 years: 38.5 years for males, and 36.3 years for females.