County · Illinois
Clark County, Illinois
Clark County, Illinois. Clark County had 15,114 residents in 2025 by the Census Bureau's estimate, down 2.4% since 2020, a steeper fall than Illinois's (−0.8%). It holds 20 places (4 cities, villages and boroughs, 15 towns and townships and 1 census-designated) and 4 census tracts. GEOID 17023.
Residents, July 2025 estimate
15,114
Census Bureau estimate (no margin published)
2020 Census count: 15,455 · ACS 2020-2024: 15,266
Median household income
$72,927
±$4,958 (90% margin)
Illinois: $83,390
Median home value
$132,400
±$15,582 (90% margin)
Illinois: $263,300
Median gross rent
$861
±$89 (90% margin)
Illinois: $1,274
How many people live in Clark County, and is it growing?
The 2020 Census counted 15,455 residents in Clark County. The Census Bureau estimates 15,114 for July 1, 2025, down 2.4% since 2020, a steeper fall than Illinois's (−0.8%). The 2020-2024 American Community Survey puts the population at 15,266 over 501 square miles of land.
| Measure | Clark County | Illinois | Change since 2015-2019 |
|---|---|---|---|
| Total population | 15,266 | 12,694,798 | −450 |
| Households | 6,555±190 | 5,036,449 | no clear change |
| Average household size | 2.29±0.07 | 2.46 | no clear change |
| Housing units | 7,307±37 | 5,457,452 | −507 |
Clark County's population since 2000
From 17,008 in 2000 to 15,114 in 2025: down 11.1%. The 2000, 2010 and 2020 figures are census counts. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); PEP Vintage 2025 (CO-EST2025); 2020 Census · Check it at data.census.gov
What cities and towns are in Clark County?
Clark County holds 20 places: 4 cities, villages and boroughs (incorporated places), 15 towns and townships (county subdivisions with their own government) and 1 census-designated place. The largest is Marshall Township with 4,469 residents (2025 estimate). Places that cross a county line are listed with the share of their 2020 residents who live in this county.
| Marshall Township | 4,581 | $81,019 |
|---|---|---|
| Marshall | 3,947 | $76,250 |
| Casey Township | 3,459 | $59,679 |
| Casey | 2,404 | $48,074 |
| Wabash Township | 2,081 | $83,431 |
| Martinsville Township | 1,542 | $67,083 |
| Martinsville | 1,118 | $61,833 |
| Westfield Township, Clark County | 658 | $70,000 |
| Westfield | 536 | $63,819 |
| York Township, Clark CountyGEOID 1702383934 | 509 | $89,167 |
| Anderson TownshipGEOID 1702301465 | 460 | $95,469 |
| Johnson Township, Clark CountyGEOID 1702338505 | 355 | $75,625 |
| Dolson TownshipGEOID 1702320279 | 353 | $61,193 |
| Darwin TownshipGEOID 1702318680 | 347 | $83,491 |
| Melrose Township, Clark CountyGEOID 1702348229 | 301 | $122,917 |
| Orange Township, Clark CountyGEOID 1702356302 | 283 | $91,563 |
| West UnionGEOID 1780879 | 271 | $109,688 |
| Auburn Township, Clark CountyGEOID 1702302908 | 230 | $73,403 |
| Parker TownshipGEOID 1702357667 | 167 | $76,641 |
| Douglas Township, Clark CountyGEOID 1702320461 | 129 | $58,177 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 place-by-county parts · Check it at data.census.gov
Who lives in Clark County?
The median resident of Clark County is 42.6 years old; 22.4% are under 18 and 20.3% are 65 or older. The largest group is non-Hispanic white residents at 95.0%, then non-Hispanic residents of two or more races at 2.5%. 1.3% of residents were born outside the United States.
| Measure | Clark County | Illinois | Change since 2015-2019 |
|---|---|---|---|
| Median age | 42.6±0.8 | 39.0 | no clear change |
| Under 18 years | 22.4% | 21.8% | – |
| 65 years and over | 20.3%±0.2 pts | 17.0% | – |
| Hispanic or Latino (any race) | 1.9% | 18.8% | +0.3 pts |
| White alone, not Hispanic | 95.0%±0.4 pts | 58.1% | −1.5 pts |
| Black or African American alone, not Hispanic | 0.5%±0.3 pts | 13.3% | no clear change |
| Asian alone, not Hispanic | 0.1%±0.1 pts | 5.9% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.0%±0.1 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0%±0.2 pts | 0.0% | – |
| Two or more races, not Hispanic | 2.5%±0.5 pts | 3.4% | – |
| Some other race alone, not Hispanic | 0.0%±0.2 pts | 0.4% | – |
| Born outside the United States | 1.3%±0.7 pts | 14.7% | no clear change |
| Speak a language other than English at home (age 5+) | 2.2%±0.8 pts | 24.0% | – |
| Civilian veterans (age 18+) | 7.8%±1.3 pts | 4.8% | – |
| With a disability | 13.6%±1.8 pts | 12.1% | – |
| No health insurance coverage | 4.7%±1.1 pts | 6.9% | no clear change |
| High school graduate or higher (age 25+) | 92.5%±1.7 pts | 90.5% | – |
| Bachelor's degree or higher (age 25+) | 24.9%±2.8 pts | 37.8% | +5.0 pts |
| Graduate or professional degree (age 25+) | 8.7%±1.9 pts | 15.3% | – |
| Moved from another state in the past year | 1.4%±1.2 pts | 1.6% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Clark County earn?
Half of Clark County's 6,555 households earn less than $72,927 a year (±$4,958), against $83,390 in Illinois. In 2015-2019 it was $69,572 in 2024 dollars; the margins of error cannot tell the two periods apart. 9.1% of residents live below the poverty line.
| Measure | Clark County | Illinois | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $72,927±$4,958 | $83,390 | no clear change |
| Mean household income | $87,731±$5,994 | $115,638 | – |
| Per capita income | $37,528±$2,437 | $46,406 | no clear change |
| People below the poverty line | 9.1%±1.9 pts | 11.8% | no clear change |
| Children under 18 below the poverty line | 9.4%±3.2 pts | 15.1% | −7.3 pts |
| Households receiving SNAP | 13.4%±2.8 pts | 13.8% | – |
| Households with a broadband subscription | 87.6%±2.3 pts | 90.8% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Clark County?
Owners occupy 80.3% of Clark County's occupied homes and renters 19.7%. The median owner-occupied home is valued at $132,400 by its owner (±$15,582). The median renter pays $861 a month including utilities, and 36.5% of renters pay 35% or more of their income on rent.
| Measure | Clark County | Illinois | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $132,400±$15,582 | $263,300 | +$18,561 |
| Median gross rent | $861±$89 | $1,274 | no clear change |
| Renters paying 35% or more of income on rent | 36.5%±10.0 pts | 39.0% | no clear change |
| Median monthly owner costs, with a mortgage | $1,233±$57 | $1,987 | – |
| Owner-occupied homes | 80.3%±3.6 pts | 67.1% | no clear change |
| Housing units | 7,307±37 | 5,457,452 | −507 |
| Homeowner vacancy rate | 2.1%±1.5 pts | 1.0% | – |
| Rental vacancy rate | 4.8%±5.3 pts | 5.0% | – |
| Single-family detached homes | 81.6%±3.0 pts | 58.2% | – |
| Mobile homes | 6.6%±1.9 pts | 2.3% | – |
| Built 2020 or later | 0.0%±0.5 pts | 0.7% | – |
| Built 1939 or earlier | 21.4%±3.2 pts | 20.2% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How many new homes is Clark County building?
Builders took permits for 9 new housing units across Clark County in 2025 (5 single-family), 0.6 per 1,000 residents.
Source: Building Permits Survey, annual county files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in Clark County get to work?
84.1% of Clark County's workers drive alone and 5.2% work from home. The average trip to work takes 25.2 minutes. The unemployment rate in 2020-2024 averaged 3.7%.
| Measure | Clark County | Illinois | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 61.3%±2.2 pts | 65.0% | – |
| Unemployment rate | 3.7%±1.3 pts | 5.8% | no clear change |
| Drove alone to work | 84.1%±3.3 pts | 65.9% | – |
| Carpooled | 8.3%±2.6 pts | 7.8% | – |
| Public transportation | 0.0%±0.1 pts | 5.8% | – |
| Walked | 1.5%±0.9 pts | 2.8% | – |
| Worked from home | 5.2%±1.8 pts | 15.9% | no clear change |
| Mean travel time to work | 25.2 min±1.8 | 27.8 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What are Clark County's census tracts?
Clark County is divided into 4 census tracts. Among those with a reliable estimate, median household income runs from $59,808 (Tract 603) to $84,007 (Tract 601).
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Check it at data.census.gov
How does Clark County compare with Illinois's other counties?
| Measure | Rank |
|---|---|
| Population | 71st of 102 |
| Growth 2020-2025 | 57th of 102 |
| Residents per square mile | 72nd of 102 |
| Median household income | 33rd of 102 |
| Median home value | 54th of 102 |
| Median gross rent | 34th of 102 |
| Poverty rate | 80th of 102 |
| Bachelor's degree or higher | 30th of 102 |
| Median age | 50th of 102 |
Source: PlainCities ranks from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Clark County are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' school search.