Union County, Illinois
County seat: Jonesboro · Population 16,656 (2025) · 413 sq mi
Union County is the 63rd most populous of Illinois's 102 counties, with 16,656 people (2025 estimate). Its county seat is Jonesboro. It is part of the Southern region, one of the 10 Illinois economic development regions (DCEO). The map shows its 6 cities and towns and the 7 neighboring counties.
Union County facts
- County seat
- Jonesboro
- Population (2025 estimate)
- 16,656 −4% since 2020
- Land area
- 413 sq mi 71st largest of 102
- Water area
- 9 sq mi
- Population density
- 40 per sq mi
- Established
- 1818
- Same name
- One of 17 Union Counties in the US
- Named after
- United States country located primarily in North America
- Largest city
- Anna 4,096
- Median household income
- $55,728
- Cities and towns
- 6
- ZIP codes
- 13
- Time zone
- Central
- FIPS code
- 17181
Cities and towns in Union County
Union County has 6 incorporated cities, towns and villages. Populations count the people living inside Union County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Anna | City | 4,096 | |
| Jonesboro (county seat) | City | 1,635 | |
| Cobden | Village | 1,024 | |
| Dongola | Village | 638 | |
| Alto Pass | Village | 300 | |
| Mill Creek | Village | 52 |
ZIP codes in Union County
13 ZIP codes reach into Union County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 62902 also Williamson and Jackson counties
- 62905 also Jackson County
- 62906
- 62912 also Johnson County
- 62920 also Jackson County
- 62923 also Johnson and Pulaski counties
- 62926 also Pulaski County
- 62939 also Johnson and Williamson counties
- 62952 also Alexander County
- 62957 also Alexander County
- 62958 also Jackson and Williamson counties
- 62961
- 62998
Population of Union County, 2020–2025
Union County shrank by 694 people (−4%) between April 2020 and July 2025: 543 more deaths than births and a net loss of 140 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 17,299 |
| 2021 | 17,049 |
| 2022 | 16,916 |
| 2023 | 16,865 |
| 2024 | 16,832 |
| 2025 | 16,656 |
Neighboring counties
- Jackson County north · 52,501 people
- Cape Girardeau County, Missouri west · 83,999 people
- Johnson County east · 13,363 people
- Alexander County south · 4,570 people
- Pulaski County south · 4,820 people
- Williamson County northeast · 67,225 people
- Perry County, Missouri northwest · 19,093 people
Printable Union 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) (89 KB)
- PNG (2400 px) (69 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.
Back to the Illinois county map with all 102 counties. Found an error? Tell us.