Clinton County, Illinois
County seat: Carlyle · Population 37,128 (2025) · 474 sq mi
Clinton County is the 35th most populous of Illinois's 102 counties, with 37,128 people (2025 estimate). Its county seat is Carlyle. It is part of the Southwest region, one of the 10 Illinois economic development regions (DCEO). The map shows its 16 cities and towns and the 6 neighboring counties.
Clinton County facts
- County seat
- Carlyle
- Population (2025 estimate)
- 37,128 +0.6% since 2020
- Land area
- 474 sq mi 58th largest of 102
- Water area
- 29 sq mi
- Population density
- 78 per sq mi
- Established
- 1824
- Same name
- One of 9 Clinton Counties in the US
- Named after
- DeWitt Clinton American politician (1769–1828)
- Largest city
- Breese 4,602
- Median household income
- $86,588
- Cities and towns
- 16
- ZIP codes
- 17
- Time zone
- Central
- FIPS code
- 17027
Cities and towns in Clinton County
Clinton County has 16 incorporated cities, towns and villages. Populations count the people living inside Clinton County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Breese | City | 4,602 | |
| Carlyle (county seat) | City | 3,188 | |
| New Baden | Village | 3,171 | St. Clair County |
| Trenton | City | 2,643 | |
| Aviston | Village | 2,454 | |
| Centralia | City | 2,258 | Jefferson, Marion and Washington counties |
| Germantown | Village | 1,379 | |
| Albers | Village | 1,114 | |
| Beckemeyer | Village | 921 | |
| Bartelso | Village | 644 | |
| Damiansville | Village | 562 | |
| St. Rose | Village | 471 | |
| Wamac | City | 451 | Marion and Washington counties |
| Hoffman | Village | 431 | |
| Keyesport | Village | 194 | Bond County |
| Huey | Village | 160 |
ZIP codes in Clinton County
17 ZIP codes reach into Clinton County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 62215
- 62216 also Madison County
- 62218
- 62219
- 62230
- 62231
- 62245
- 62249 also Madison and Bond counties
- 62250
- 62253 also Bond and Fayette counties
- 62265 also St. Clair County
- 62266
- 62275 also Bond and Madison counties
- 62293 also St. Clair and Madison counties
- 62801 also Marion, Washington and Jefferson counties
- 62875 also Marion and Fayette counties
- 62882 also Marion County
Population of Clinton County, 2020–2025
Clinton County grew by 224 people (+0.6%) between April 2020 and July 2025: 35 more births than deaths and a net gain of 180 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 36,915 |
| 2021 | 36,915 |
| 2022 | 37,051 |
| 2023 | 36,938 |
| 2024 | 37,088 |
| 2025 | 37,128 |
Neighboring counties
- Washington County south · 13,564 people
- Bond County north · 16,959 people
- St. Clair County west · 250,708 people
- Marion County east · 36,382 people
- Madison County northwest · 263,110 people
- Fayette County northeast · 20,790 people
Printable Clinton County map
The PDF is a vector file with real text: it prints sharp on Letter paper and you can search it for a town. The PNG is 2400 pixels wide for slides and documents. Both are free to use with a credit to WhichCounty.
- PDF (Letter) (115 KB)
- PNG (2400 px) (76 KB)
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Sources
- Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files (1:500,000).
- Population: Census Bureau county and city estimates, Vintage 2025. CDP populations: American Community Survey 2020–2024.
- Places and ZIP codes: Census Bureau 2026 Gazetteer and 2020 ZIP Code Tabulation Area relationship files.
- County seat, founding year and name origin: Wikidata (CC0), checked against state sources.
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