• county
  • FIPS 17023
  • Largest town: Marshall

Clark County, Illinois

Clark County had 15,076 residents in the Census Vintage 2024 estimate, on 501.4 square miles of land. It ranks 71st of 102 in Illinois by population and 53rd by land area.

Population
15,076
#71 of 102 in Illinois · #2,091 in US
Area
501.4 sq mi
#53 of 102 in Illinois · #2,075 in US
Density
30 / sq mi
#71 of 102 in Illinois · #1,923 in US
Median household income
$66,923
#47 of 102 in Illinois · #1,216 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Clark County within Illinois. Pin: Springfield.

Measure from here

Tools and pages that start from Clark County

Clark County population, land area and income

Clark County had 15,076 residents in the Census Vintage 2024 estimate, on 501.4 square miles of land. It ranks 71st of 102 in Illinois by population and 53rd by land area. That works out to 30.1 people per square mile, below the US average of 96.3, and below the national county median.

The median county-equivalent in Illinois has 24,447 residents; Clark County is somewhat smaller.

Its SAIPE 2023 median household income of $66,923 is above the national county median among 3,143 counties with an estimate.

National rank among 3,144

Population

15,076

3144th1st

2091st of 3,144 (US)

Land area

501 sq mi

3144th1st

2075th of 3,144 (US)

Density

30.1 / sq mi

3144th1st

1923rd of 3,144 (US)

Median household income

$66,923

3143rd1st

1216th of 3,143 (US)

Rank within Illinois (102)

Population

15,076

102nd1st

71st of 102 (IL)

Land area

501 sq mi

102nd1st

53rd of 102 (IL)

Density

30.1 / sq mi

102nd1st

71st of 102 (IL)

Median household income

$66,923

102nd1st

47th of 102 (IL)

How Clark County's population changed since 2020

Clark County lost 372 residents between the July 2020 and July 2024 estimates, a drop of 2.4%. That ranks 70th of 102 in Illinois for growth. The median Illinois county changed by -1.7%, and the state as a whole by -0.7%.

Since the April 2020 estimates base, Clark County recorded 601 births and 942 deaths, a natural change of -341. Net international migration added +51 and net domestic migration, people moving to or from other US counties, came to -108. The largest single component was natural change, which removed 341 people.

15.4k202015.4k202115.2k202215.2k202315.1k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
601
Deaths
942
Net international migration
+51
Net domestic migration
-108
Change, July 2023 to July 2024
-142

Where Clark County is

The Census internal point of Clark County is at 39.332300, -87.791700. It sits in UTM zone 16N. The map shades Illinois's 102 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Clark County outlined. Dots are towns of 1,000+ people with residents in it.

Piatt County: -0.3%Hamilton County: -2.2%Williamson County: -0.1%Edgar County: -2.4%Macoupin County: -2.3%Marshall County: -1.3%Putnam County: +0.0%Richland County: -2.8%Washington County: -1.4%Lee County: -1.5%Douglas County: +0.2%Cook County: -1.6%Effingham County: -0.3%Edwards County: -3.6%Cass County: -2.0%Clay County: -3.4%Knox County: -2.2%LaSalle County: -0.9%Cumberland County: -1.3%Warren County: -3.7%Moultrie County: -0.9%Menard County: -2.5%Fayette County: -1.5%Boone County: -0.0%Lawrence County: -3.2%Marion County: -3.2%Champaign County: +3.0%Clark County: -2.4%Ford County: -0.4%Wayne County: -1.4%Logan County: -1.4%Grundy County: +2.5%Jasper County: -1.8%Crawford County: -1.3%McDonough County: -1.7%Clinton County: +0.5%Perry County: -3.0%Montgomery County: -2.2%Henry County: -2.0%Livingston County: -1.2%Scott County: -3.8%Alexander County: -11.2%Bureau County: -2.2%Brown County: +1.1%Mason County: -3.9%Calhoun County: -4.1%Greene County: -4.3%Coles County: -1.4%Kendall County: +8.2%Lake County: +0.7%Mercer County: -2.2%St. Clair County: -2.3%Wabash County: -3.0%Bond County: -1.7%DuPage County: +0.6%Gallatin County: -5.2%Stephenson County: -3.3%McHenry County: +1.9%White County: -3.0%Saline County: -3.9%Christian County: -2.2%Sangamon County: -1.0%Massac County: -3.6%Macon County: -2.9%Johnson County: -0.0%Jo Daviess County: -2.6%Peoria County: -1.0%DeKalb County: +1.0%Pope County: -1.5%De Witt County: -0.9%Schuyler County: -1.7%Fulton County: -3.1%Ogle County: -0.8%Jersey County: -1.6%Iroquois County: -3.3%Kankakee County: -0.9%Rock Island County: -1.1%Pulaski County: -5.8%Kane County: +0.9%Union County: -2.4%Whiteside County: -1.7%Woodford County: -0.3%Carroll County: -1.5%Adams County: -2.3%Hardin County: -2.6%Madison County: -1.0%Hancock County: -3.1%Monroe County: +0.0%Tazewell County: -1.1%Jackson County: -0.1%Vermilion County: -3.9%Randolph County: -0.6%McLean County: +0.5%Morgan County: -2.6%Shelby County: -1.7%Will County: +1.7%Winnebago County: -0.4%Jefferson County: -2.4%Stark County: -2.2%Henderson County: -4.5%Pike County: -2.6%Franklin County: -1.8%
Change 2020 to 2024
  1. < -3.0%
  2. < -2.2%
  3. < -1.4%
  4. < -0.3%
  5. ≥ -0.3%
no data

Orange pin: Clark County internal point. Dark pin: Springfield.

Internal point

Decimal
39.332300, -87.791700
DMS
39°19'56.28"N 87°47'30.12"W
UTM
16N 431766.7E 4353952.1N
Geohash
dncxf20p3
Plus code
86FJ86J5+W8

Towns in Clark County

3 incorporated places of 1,000+ people have residents in Clark County, 7,313 people together, or 49% of the county. Each figure counts only the part of the town inside Clark County; towns marked "part" extend into another county. The largest is Marshall with 3,865.

  1. 01Marshall3,865
  2. 02Casey (part)2,365
  3. 03Martinsville1,083
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Clark County

The Census 2024 county adjacency file lists 7 neighbors for Clark County, including 2 across a state line. The most populous is Vigo County, IN, with 106,166 residents. Distances run between Census internal points in a straight line.

Distance to Springfield and the nearest big city

Springfield is 103.7 miles WNW of Clark County's internal point in a straight line. The nearest place of 100,000 or more is Indianapolis, IN (population 891,484), 92.9 miles away. The nearest place of 10,000 or more is Charleston, IL (population 17,361), 23.1 miles away.

Clark County FIPS code

The FIPS code of Clark County is 17023: state code 17 for Illinois plus county code 023. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $66,923.

Questions people ask

What is the population of Clark County, Illinois?

The Census Vintage 2024 estimate for July 1, 2024 is 15,076. That is down 372 people (2.4%) from the July 2020 estimate of 15,448.

What is the FIPS code of Clark County?

17023. The first two digits (17) are Illinois; the last three (023) identify the county.

What is the largest town in Clark County?

Marshall, with 3,865 residents inside Clark County in 2024.

Which counties border Clark County?

7 county-equivalents border it in the Census 2024 adjacency file: Vigo County, IN; Coles County, IL; Sullivan County, IN; Crawford County, IL; Edgar County, IL; Cumberland County, IL; Jasper County, IL.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.