Iroquois County, Illinois
County seat: Watseka · Population 26,150 (2025) · 1,117 sq mi
Iroquois County is the 50th most populous of Illinois's 102 counties, with 26,150 people (2025 estimate). Its county seat is Watseka. It is part of the East Central region, one of the 10 Illinois economic development regions (DCEO). The map shows its 21 cities and towns and the 5 neighboring counties.
Iroquois County facts
- County seat
- Watseka
- Population (2025 estimate)
- 26,150 −3.4% since 2020
- Land area
- 1,117 sq mi 3rd largest of 102
- Water area
- 2 sq mi
- Population density
- 23 per sq mi
- Established
- 1833
- Named after
- Iroquois River river in Illinois, United States
- Largest city
- Watseka 4,510
- Median household income
- $66,255
- Cities and towns
- 21
- ZIP codes
- 28
- Time zone
- Central
- FIPS code
- 17075
Cities and towns in Iroquois County
Iroquois County has 21 incorporated cities, towns and villages. Populations count the people living inside Iroquois County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Watseka (county seat) | City | 4,510 | |
| Gilman | City | 1,681 | |
| Onarga | Village | 1,305 | |
| Clifton | Village | 1,298 | |
| Milford | Village | 1,116 | |
| Sheldon | Village | 931 | |
| Cissna Park | Village | 780 | |
| Ashkum | Village | 718 | |
| Chebanse | Village | 629 | Kankakee County |
| Danforth | Village | 569 | |
| Crescent City | Village | 529 | |
| Buckley | Village | 462 | |
| Loda | Village | 329 | |
| Martinton | Village | 317 | |
| Beaverville | Village | 295 | |
| Donovan | Village | 239 | |
| Woodland | Village | 237 | |
| Thawville | Village | 207 | |
| Wellington | Village | 197 | |
| Papineau | Village | 132 | |
| Iroquois | Village | 131 |
ZIP codes in Iroquois County
28 ZIP codes reach into Iroquois County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 60911
- 60912
- 60918 also Ford County
- 60922 also Kankakee County
- 60924
- 60926
- 60927
- 60928
- 60930
- 60931
- 60938
- 60939
- 60941 also Kankakee and Ford counties
- 60942 also Vermilion County
- 60945
- 60948 also Ford County
- 60951
- 60953
- 60955
- 60956
- 60960 also Vermilion, Ford and Champaign counties
- 60964 also Kankakee County
- 60966
- 60967
- 60968 also Ford and Livingston counties
- 60970
- 60973
- 60974
Population of Iroquois County, 2020–2025
Iroquois County shrank by 916 people (−3.4%) between April 2020 and July 2025: 752 more deaths than births and a net loss of 167 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 26,967 |
| 2021 | 26,770 |
| 2022 | 26,421 |
| 2023 | 26,135 |
| 2024 | 26,222 |
| 2025 | 26,150 |
Neighboring counties
- Ford County southwest · 13,216 people
- Kankakee County north · 105,525 people
- Vermilion County south · 71,259 people
- Newton County, Indiana northeast · 14,188 people
- Benton County, Indiana east · 8,883 people
Printable Iroquois 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) (111 KB)
- PNG (2400 px) (87 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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