Clinton County's 2026 population is estimated at 37,489, reflecting a 0.54% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Clinton County is the 35th largest county in Illinois. The 2010 population was 37,833 and has grown -0.91% since 2010.
Data after 2023 is projected based on recent change
Overall: 41.5 years
Female: 42.8 years
Male: 40.3 years
There are 28,974 adults, (6,955 of whom are seniors) in Clinton County.
Female: 17,811 (48.2%)
Male: 19,143 (51.8%)
The racial composition of Clinton County includes 90.88% White, 3.15% Black or African American, and smaller percentages for other race, Asian, Native American and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 33,584 | 90.88% |
| Two or more races | 1,595 | 4.32% |
| Black or African American | 1,164 | 3.15% |
| Other race | 303 | 0.82% |
| Asian | 231 | 0.63% |
| Native American | 77 | 0.21% |
Clinton County 's average per capita income is $56,058. Household income levels show a median of $86,588. The poverty rate stands at 7.37%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $117,424 | - |
| Families | $107,315 | $127,694 |
| Households | $86,588 | $108,402 |
| Non Families | $44,186 | $65,552 |
Average Income
Median Household Income
Poverty Rate
