Clinton County, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 37th-largest in Illinois
The population of Clinton County, Illinois is 36,899 as of the 2023 American Community Survey, making it the 37th-largest county in Illinois. The median household income is $82,314, the median home value is $180,500, and the median age is 41.4.
The population of Clinton County has declined 2.0% since 2010 (37,833 → 37,087), a -0.14% annualized rate.
36,899
Population
-0.14%
Annual growth
78
People / sq mi
$82,314
Median Income
$180,500
Median Home Value
Clinton County covers 474 sq mi of land at 77.9 people per square mile.
About Clinton County, IL
Clinton County is a county in Illinois with a population of 36,899. It ranks #37 among counties in Illinois by population. The median age is 41.4, older than the national median. The population is 51.8% male and 48.2% female.
The median household income in Clinton County is $82,314, above the US median of $74,580. 5.7% of residents live below the federal poverty level. Home values sit at a median of $180,500, with monthly rent averaging $934. The homeownership rate of 79.3% is higher than the national rate of 64.8%.
Educational attainment in Clinton County reflects 24.4% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 11.1% of workers primarily work from home, below the national work-from-home rate of 14.2%. The average commute is 25.7 minutes each way.
Clinton County Population History (2010-2024)
The county of Clinton County had a population of 37,833 in 2010 and 37,087 in 2024, a -2.0% growth over 14 years. The peak was 38,024 in 2011. Average annual growth rate: -0.14%.
37,087
Population (2024)
37,833
Population (2010)
38,024
Peak (2011)
-0.14%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 37,833 |
| 2011 | 38,024 |
| 2012 | 37,908 |
| 2013 | 37,725 |
| 2014 | 37,637 |
| 2015 | 37,657 |
| 2016 | 37,594 |
| 2017 | 37,649 |
| 2018 | 37,666 |
| 2019 | 37,440 |
| 2020 | 36,913 |
| 2021 | 36,898 |
| 2022 | 36,987 |
| 2023 | 36,886 |
| 2024 | 37,087 |
Race & Ethnicity
| White | 91.4% |
| Black or African American | 3.2% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.1% |
| Two or More Races | 0.0% |
Age & Sex
41.4
Median Age
48.2%
Female
51.8%
Male
18.2%
Age 65+
Age Distribution
Children (under 15): 17.7% · Seniors (65+): 18.2%
Income & Poverty
| Median household income | $82,314+$612 vs state |
| Mean household income | $104,928 |
| Per-capita income | $41,334 |
| Poverty rate | 5.7%-2.5% vs state |
| Unemployment rate | 2.0% |
| Employment-to-population | 60.3% |
Top Industries by Employment
The largest employment sector in Clinton County is professional & business services, accounting for 24.7% of workers.
How residents commute
0.5%
Drive alone
2.4%
Carpool
79.1%
Public transit
11.1%
Work from home
25.7 min
Avg commute
Housing
$180,500$-70,000 vs state
Median home value
$934
Median rent
79.3%
Homeownership rate
15,677
Total housing units
92.3%
Occupied
7.7%
Vacant
20.7%
Renter-occupied
Social & access
95.1%
With health insurance
92.8%
With broadband internet
17.0%
Foreign-born
8.9%
Veterans (18+)
13.6%
With a disability
95.9%
Speak language other than English at home
Education
92.0%
High School+
24.4%
Bachelor's+
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Other counties in Illinois
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County rankings
Frequently Asked Questions
Clinton County, Illinois has a population of 36,899 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 37th-largest county in Illinois. Population density is 78 people per square mile.
The population of Clinton County has declined 2.0% since 2010 (37,833 → 37,087), a -0.14% annualized rate.
The median household income in Clinton County, Illinois is $82,314, with mean (average) household income of $104,928 and per-capita income of $41,334. 5.7% of residents live below the federal poverty level.
In Clinton County, the largest racial and ethnic groups are White (91.4%), Black or African American (3.2%), Hispanic or Latino (1.1%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Clinton County, Illinois is 41.4 years. Residents are 48.2% female and 51.8% male.
The median home value in Clinton County is $180,500 and median monthly rent is $934. 79.3% of occupied housing units are owner-occupied. The county has 15,677 total housing units, 7.7% of which are vacant.
The largest employment sector in Clinton County, Illinois is professional, scientific, and management services, employing 24.7% of workers. The unemployment rate is 2.0%.
Chicago is among the largest cities associated with Clinton County, Illinois, with a population of 2,707,648.
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Statewide data for Illinois
Population, race, income, age, and trends across Illinois
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.