Total Population in St. Clair County, IL
ACS 2024 5-Year Estimates
253,694
Rank #284/3,222 · #9 in IL
91th
St. Clair 253,694
IL 13M -98.0%
US 330M
Total Population Trend
Rankings →Percentile Rank Over Time
Year-over-Year Population Change
National Distribution
How St. Clair County's total population of 253,694 compares to all 3,222 U.S. counties. Values range from 33 to 9,808,667.
Distribution of Total Population Across All Counties
Ranking Context
Counties ranked closest to St. Clair County for total population.
Nearby Rankings
Full ranking →| #281 | Washington County, AR | 256,765 |
| #282 | Sussex County, DE | 255,626 |
| #283 | Jefferson County, TX | 253,878 |
| #284 | St. Clair County, IL | 253,694 |
| #285 | Chesapeake city, VA | 252,583 |
| #286 | Union County, NC | 250,958 |
| #287 | Canyon County, ID | 250,790 |
About Total Population
St. Clair County, Illinois has a total population of 253,694, ranking #284 of 3,222 counties nationwide — 99.9% below the national value of 330M. Within Illinois, it ranks #9 of 102. This places it in the 91th percentile nationally.
Total population count from the American Community Survey. 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.