Clark County, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 71st-largest in Illinois
The population of Clark County, Illinois is 15,328 as of the 2023 American Community Survey, making it the 71st-largest county in Illinois. The median household income is $70,625, the median home value is $123,100, and the median age is 42.0.
The population of Clark County has declined 7.5% since 2010 (16,291 → 15,076), a -0.55% annualized rate.
15,328
Population
-0.55%
Annual growth
31
People / sq mi
$70,625
Median Income
$123,100
Median Home Value
Clark County covers 501 sq mi of land at 30.6 people per square mile.
About Clark County, IL
Clark County is a county in Illinois with a population of 15,328. It ranks #71 among counties in Illinois by population. The median age is 42.0, older than the national median. The population is 50.0% male and 50.0% female.
The median household income in Clark County is $70,625, below the US median of $74,580. 7.8% of residents live below the federal poverty level. Home values sit at a median of $123,100, with monthly rent averaging $828. The homeownership rate of 81.7% is higher than the national rate of 64.8%.
Educational attainment in Clark County reflects 24.3% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 5.4% 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.
Clark County Population History (2010-2024)
The county of Clark County had a population of 16,291 in 2010 and 15,076 in 2024, a -7.5% growth over 14 years. The peak was 16,291 in 2010. Average annual growth rate: -0.55%.
15,076
Population (2024)
16,291
Population (2010)
16,291
Peak (2010)
-0.55%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 16,291 |
| 2011 | 16,205 |
| 2012 | 16,265 |
| 2013 | 16,105 |
| 2014 | 16,060 |
| 2015 | 15,881 |
| 2016 | 15,860 |
| 2017 | 15,824 |
| 2018 | 15,594 |
| 2019 | 15,465 |
| 2020 | 15,448 |
| 2021 | 15,375 |
| 2022 | 15,211 |
| 2023 | 15,218 |
| 2024 | 15,076 |
Race & Ethnicity
| White | 95.9% |
| Black or African American | 0.7% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.7% |
| Two or More Races | 0.0% |
Age & Sex
42.0
Median Age
50.0%
Female
50.0%
Male
19.7%
Age 65+
Age Distribution
Children (under 15): 18.3% · Seniors (65+): 19.7%
Income & Poverty
| Median household income | $70,625$-11,077 vs state |
| Mean household income | $83,186 |
| Per-capita income | $35,425 |
| Poverty rate | 7.8%-0.4% vs state |
| Unemployment rate | 2.4% |
| Employment-to-population | 57.2% |
Top Industries by Employment
The largest employment sector in Clark County is professional & business services, accounting for 25.0% of workers.
How residents commute
0.3%
Drive alone
1.2%
Carpool
82.1%
Public transit
5.4%
Work from home
25.7 min
Avg commute
Housing
$123,100$-127,400 vs state
Median home value
$828
Median rent
81.7%
Homeownership rate
7,333
Total housing units
90.0%
Occupied
10.0%
Vacant
18.3%
Renter-occupied
Social & access
95.1%
With health insurance
90.6%
With broadband internet
52.4%
Foreign-born
7.9%
Veterans (18+)
13.5%
With a disability
97.8%
Speak language other than English at home
Education
92.0%
High School+
24.3%
Bachelor's+
Largest cities in Illinois
Other counties in Illinois
Part of Illinois
Metro areas in Illinois
County rankings
Frequently Asked Questions
Clark County, Illinois has a population of 15,328 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 71st-largest county in Illinois. Population density is 31 people per square mile.
The population of Clark County has declined 7.5% since 2010 (16,291 → 15,076), a -0.55% annualized rate.
The median household income in Clark County, Illinois is $70,625, with mean (average) household income of $83,186 and per-capita income of $35,425. 7.8% of residents live below the federal poverty level.
In Clark County, the largest racial and ethnic groups are White (95.9%), Hispanic or Latino (1.7%), Black or African American (0.7%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Clark County, Illinois is 42.0 years. Residents are 50.0% female and 50.0% male.
The median home value in Clark County is $123,100 and median monthly rent is $828. 81.7% of occupied housing units are owner-occupied. The county has 7,333 total housing units, 10.0% of which are vacant.
The largest employment sector in Clark County, Illinois is professional, scientific, and management services, employing 25.0% of workers. The unemployment rate is 2.4%.
Chicago is among the largest cities associated with Clark County, Illinois, with a population of 2,707,648.
More from Illinois
Population 5,185,812
Population 927,263
Population 711,885
Population 698,450
Full rankings of Illinois counties
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.