Salem is a city located in Marion County Illinois. It is also the county seat of Marion County. With a 2020 population of 6,891, it is the 281st largest city in Illinois and the 3989th largest city in the United States . Salem is currently declining at a rate of -0.58% annually and its population has decreased by -7.94% since the most recent census, which recorded a population of 7,485 in 2010. Salem reached it's highest population of 7,909 in 2000. Spanning over 7 miles, Salem has a population density of 991 people per square mile.
The average household income in Salem is $51,528 with a poverty rate of 23.00%. The median rental costs in recent years comes to $620 per month, and the median house value is $78,500. The median age in Salem is 36.6 years, 33.6 years for males, and 41.7 years for females.