Winnebago County, Illinois
County seat: Rockford · Population 283,674 (2025) · 513 sq mi
Winnebago County is the 7th most populous of Illinois's 102 counties, with 283,674 people (2025 estimate). Its county seat is Rockford. It is part of the Northern Stateline region, one of the 10 Illinois economic development regions (DCEO). The map shows its 11 cities and towns and the 6 neighboring counties.
Winnebago County facts
- County seat
- Rockford
- Population (2025 estimate)
- 283,674 −0.6% since 2020
- Land area
- 513 sq mi 51st largest of 102
- Water area
- 6 sq mi
- Population density
- 553 per sq mi
- Established
- 1836
- Same name
- One of 3 Winnebago Counties in the US
- Named after
- Ho-Chunk Siouan-speaking Native American people
- Largest city
- Rockford 147,384 in the county
- Median household income
- $65,837
- Cities and towns
- 11 plus 3 CDPs
- ZIP codes
- 26
- Time zone
- Central
- FIPS code
- 17201
Cities and towns in Winnebago County
Winnebago County has 11 incorporated cities, towns and villages. Populations count the people living inside Winnebago County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Rockford (county seat) | City | 147,384 | Ogle County |
| Machesney Park | Village | 22,805 | |
| Loves Park | City | 22,086 | Boone County |
| Roscoe | Village | 11,034 | |
| South Beloit | City | 7,996 | |
| Rockton | Village | 7,870 | |
| Winnebago | Village | 2,903 | |
| Cherry Valley | Village | 2,547 | Boone County |
| Pecatonica | Village | 2,052 | |
| Durand | Village | 1,380 | |
| New Milford | Village | 808 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Westlake Village | 1,414 | |
| Lake Summerset | 1,147 | Stephenson County |
| Argyle | 214 | Boone County |
ZIP codes in Winnebago County
26 ZIP codes reach into Winnebago County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 61008 also Boone County
- 61011 also Boone County
- 61016 also Boone County
- 61019 also Stephenson County
- 61020 also Ogle County
- 61024
- 61047 also Ogle and Stephenson counties
- 61063 also Stephenson County
- 61072
- 61073 also Boone County
- 61077
- 61079
- 61080 also Boone County
- 61084 also Ogle County
- 61088 also Ogle County
- 61101
- 61102 also Ogle County
- 61103
- 61104
- 61107 also Boone County
- 61108
- 61109 also Ogle County
- 61111 also Boone County
- 61112
- 61114 also Boone County
- 61115
Population of Winnebago County, 2020–2025
Winnebago County shrank by 1,677 people (−0.6%) between April 2020 and July 2025: 807 more deaths than births and a net loss of 916 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 284,939 |
| 2021 | 283,436 |
| 2022 | 281,767 |
| 2023 | 281,732 |
| 2024 | 282,965 |
| 2025 | 283,674 |
Neighboring counties
- Ogle County south · 51,399 people
- Boone County east · 53,568 people
- Rock County, Wisconsin north · 166,472 people
- Stephenson County west · 43,220 people
- Green County, Wisconsin northwest · 37,227 people
- DeKalb County southeast · 101,835 people
Printable Winnebago 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) (75 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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