Randolph County, Illinois
County seat: Chester · Population 29,921 (2025) · 575 sq mi
Randolph County is the 47th most populous of Illinois's 102 counties, with 29,921 people (2025 estimate). Its county seat is Chester. It is part of the Southwest region, one of the 10 Illinois economic development regions (DCEO). The map shows its 14 cities and towns and the 7 neighboring counties.
Randolph County facts
- County seat
- Chester
- Population (2025 estimate)
- 29,921 −0.8% since 2020
- Land area
- 575 sq mi 39th largest of 102
- Water area
- 22 sq mi
- Population density
- 52 per sq mi
- Established
- 1795
- Same name
- One of 8 Randolph Counties in the US
- Named after
- Edmund Randolph American attorney (1753-1813)
- Largest city
- Chester 6,847
- Median household income
- $68,131
- Cities and towns
- 14
- ZIP codes
- 18
- Time zone
- Central
- FIPS code
- 17157
Cities and towns in Randolph County
Randolph County has 14 incorporated cities, towns and villages. Populations count the people living inside Randolph County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Chester (county seat) | City | 6,847 | |
| Sparta | City | 4,022 | |
| Red Bud | City | 3,761 | |
| Steeleville | Village | 1,883 | |
| Percy | Village | 905 | |
| Coulterville | Village | 825 | |
| Tilden | Village | 745 | |
| Evansville | Village | 533 | |
| Prairie du Rocher | Village | 510 | |
| Ellis Grove | Village | 324 | |
| Baldwin | Village | 313 | |
| Ruma | Village | 313 | |
| Rockwood | Village | 32 | |
| Kaskaskia | Village | 22 |
ZIP codes in Randolph County
18 ZIP codes reach into Randolph County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 62217
- 62233
- 62237 also Perry and Washington counties
- 62241
- 62242
- 62257 also St. Clair and Washington counties
- 62261
- 62272 also Perry and Jackson counties
- 62277 also Monroe County
- 62278 also Monroe County
- 62280 also Jackson County
- 62286
- 62288
- 62292
- 62297
- 62907 also Jackson County
- 62916 also Jackson and Perry counties
- 63673
Population of Randolph County, 2020–2025
Randolph County shrank by 244 people (−0.8%) between April 2020 and July 2025: 595 more deaths than births and a net gain of 345 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 30,091 |
| 2021 | 30,215 |
| 2022 | 29,942 |
| 2023 | 29,805 |
| 2024 | 29,870 |
| 2025 | 29,921 |
Neighboring counties
- Ste. Genevieve County, Missouri southwest · 18,689 people
- Monroe County northwest · 34,840 people
- Perry County, Missouri south · 19,093 people
- Perry County east · 20,160 people
- Jackson County southeast · 52,501 people
- St. Clair County north · 250,708 people
- Washington County northeast · 13,564 people
Printable Randolph 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) (106 KB)
- PNG (2400 px) (84 KB)
Paste this code to embed the map on your site:
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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