
Salem
- County:
- Marion County
- County Seat:
- Yes
- Area (mi²):
- 6.991
- State:
- Illinois
Salem is a city located in Marion County, Illinois. Salem has a 2025 population of 6,917. It is also the county seat of Marion County. Salem is currently declining at a rate of -0.99% annually and its population has decreased by -4.78% since the most recent census, which recorded a population of 7,264 in 2020.
The average household income in Salem is $73,933 with a poverty rate of 20.12%. The median age in Salem is 38.2 years: 37.8 years for males, and 38.7 years for females.