Median Age in Marion County, IL
ACS 2024 5-Year Estimates
41.5 years
Rank #1,643/3,222 · #63 in IL
49th
Marion 41.5 years
IL 39.0 years +6.4%
US 38.9 years +6.7%
Median Age Trend
Rankings →Percentile Rank Over Time
Year-over-Year Age Change
National Distribution
How Marion County's median age of 41.5 years compares to all 3,222 U.S. counties. Values range from 21.4 years to 86.2 years.
Distribution of Median Age Across All Counties
Ranking Context
Counties ranked closest to Marion County for median age.
Nearby Rankings
Full ranking →| #1,640 | Schley County, GA | 41.5 years |
| #1,641 | Wilcox County, GA | 41.5 years |
| #1,642 | Clinton County, IL | 41.5 years |
| #1,643 | Marion County, IL | 41.5 years |
| #1,644 | Miami County, IN | 41.5 years |
| #1,645 | Shelby County, IN | 41.5 years |
| #1,646 | Washington County, IN | 41.5 years |
About Median Age
Marion County, Illinois has a median age of 41.5 years, ranking #1,643 of 3,222 counties nationwide — 6.7% above the national value of 38.9 years. Within Illinois, it ranks #63 of 102. This places it in the 49th percentile nationally.
The median age of the total population. Source: U.S. Census Bureau, American Community Survey 2024 5-Year Estimates. All values are estimates derived from survey samples and are subject to margin of error. For more information, see our methodology.