Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

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zipcodes.pro — STATE/IL/COUNTY/CLARK

Clark County, IL ZIP codes

There are 7 ZIP codes in Clark County, IL, in 7 towns, from 62420 to 62478. The largest are 62441 (Marshall), 62420 (Casey) and 62442 (Martinsville).

The county seat is Marshall.

ZIP codes
7
Towns
7
County seat
Marshall
County FIPS
17023
Population
15,266
Median household income
$72,927
Land area
501 sq mi

Clark County ZIP codes by town

Marshall (county seat)
62441

Each ZIP code is listed under the county most of its land lies in and the town the Postal Service names it for; a ZIP code's own page shows exactly how it is split.

Map of Clark County ZIP codes

62420624236244162442624746247762478

The ZIP codes of Clark County, shaded. Outlines are Census ZIP Code Tabulation Areas (2020), which approximate the mail routes; PO-box and single-address codes have no area and are not drawn. Click any area to open its ZIP code.

Clark County in numbers

About 15,266 people live in Clark County, in 6,555 households, the 71st most populous of Illinois's 102 counties. The median household income is $72,927 a year, 13% below the Illinois median of $83,390 (US: $80,734). The median owner-occupied home is valued at $132,400 (50% below the Illinois median), and median gross rent is $861 a month. The median age is 42.6; 24.9% of adults 25 and over hold a bachelor's degree or higher (37.8% across Illinois); the average commute takes 25 minutes.

Population15,266Clark15,266
Households6,555Clark6,555
Median age42.6Clark42.6Illinois39.0US 38.9
Median household income$72,927Clark$72,927Illinois$83,390US $80,734
Median home value$132,400Clark$132,400Illinois$263,300US $332,700
Median gross rent$861Clark$861Illinois$1,274US $1,413
Bachelor's degree or higher24.9%Clark24.9%Illinois37.8%US 35.7%
Mean commute25.2 minClark25.2 minIllinois27.8 minUS 26.4 min
Population density30 / sq miClark30 / sq mi

U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates. Survey estimates carry margins of error, wider for small places. Sources and methods.

Largest towns in Clark County

Largest towns in Clark County
TownZIP codesPopulation
Marshall 1 4,040
Casey 1 2,239
Martinsville 1 1,187
Dennison 1 546
Westfield 1 415
West Union 1 140
West York 1 83

Population of the census place of that name where there is one, otherwise of the ZIP codes the Postal Service addresses by it. A town's ZIP codes can reach past the county line.

Neighbouring counties

Counties that share a ZIP code with Clark County.

Not sure you are in Clark County? What county am I in? answers from your location, near a county line included.

Every ZIP code in Clark County, with figures

ZIP codes in Clark County
ZIP City Type Population Median income Median home
62420 Casey , IL Standard 4,299 $65,771 $140,400
62423 Dennison , IL Standard 546 $47,179 $173,300
62441 Marshall , IL Standard 7,003 $80,738 $155,600
62442 Martinsville , IL Standard 2,671 $70,284 $87,200
62474 Westfield , IL Standard 626 $67,083 $88,200
62477 West Union , IL Standard 526 $88,646 $110,900
62478 West York , IL Standard 333 $98,750 $131,000

Cite this page

zipcodes.pro. “Clark County ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/state/il/county/clark

Underlying data is public domain or openly licensed — sources, vintages and licences.