Marion Flag

Marion

County Seat:
Yes
Area (mi²):
14.403
State:
Illinois

Marion is a city located in Williamson County, Illinois. Marion has a 2025 population of 16,860. It is also the county seat of Williamson CountyMarion is currently growing at a rate of 0.02% annually and its population has increased by 0.12% since the most recent census, which recorded a population of 16,840 in 2020.

The average household income in Marion is $78,411 with a poverty rate of 15.97%.The median age in Marion is 40.4 years: 39.5 years for males, and 41.3 years for females.

16.9K
Total Population
1,171
Density (mi²)
4 0.02%
Growth

Marion Population

Demographics

Economics and Income Statistics

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)