Whiteside County, Illinois
County seat: Morrison · Population 54,121 (2025) · 684 sq mi
Whiteside County is the 24th most populous of Illinois's 102 counties, with 54,121 people (2025 estimate). Its county seat is Morrison. It is part of the Northwest region, one of the 10 Illinois economic development regions (DCEO). The map shows its 11 cities and towns and the 7 neighboring counties.
Whiteside County facts
- County seat
- Morrison
- Population (2025 estimate)
- 54,121 −2.8% since 2020
- Land area
- 684 sq mi 26th largest of 102
- Water area
- 12 sq mi
- Population density
- 79 per sq mi
- Established
- 1836
- Named after
- Samuel Whiteside American politician and soldier (1783–1866)
- Largest city
- Sterling 14,394
- Median household income
- $67,500
- Cities and towns
- 11 plus 2 CDPs
- ZIP codes
- 15
- Time zone
- Central
- FIPS code
- 17195
Cities and towns in Whiteside County
Whiteside County has 11 incorporated cities, towns and villages. Populations count the people living inside Whiteside County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Sterling | City | 14,394 | |
| Rock Falls | City | 8,521 | |
| Morrison (county seat) | City | 3,945 | |
| Fulton | City | 3,540 | |
| Prophetstown | City | 1,887 | |
| Erie | Village | 1,484 | |
| Albany | Village | 838 | |
| Tampico | Village | 668 | |
| Lyndon | Village | 526 | |
| Coleta | Village | 159 | |
| Deer Grove | Village | 39 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Como | 535 | |
| Galt | 213 |
ZIP codes in Whiteside County
15 ZIP codes reach into Whiteside County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 61014 also Carroll County
- 61037
- 61064 also Ogle, Carroll and Lee counties
- 61071 also Lee County
- 61081 also Lee County
- 61230
- 61243 also Lee County
- 61250 also Henry County
- 61251
- 61252
- 61254 also Henry County
- 61261
- 61270 also Carroll County
- 61277 also Henry County
- 61283 also Bureau and Henry counties
Population of Whiteside County, 2020–2025
Whiteside County shrank by 1,567 people (−2.8%) between April 2020 and July 2025: 1,215 more deaths than births and a net loss of 365 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 55,555 |
| 2021 | 55,299 |
| 2022 | 54,552 |
| 2023 | 54,480 |
| 2024 | 54,423 |
| 2025 | 54,121 |
Neighboring counties
- Carroll County north · 15,419 people
- Lee County east · 32,914 people
- Rock Island County southwest · 141,869 people
- Henry County south · 48,095 people
- Clinton County, Iowa west · 46,002 people
- Bureau County southeast · 32,510 people
- Ogle County northeast · 51,399 people
Printable Whiteside 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) (93 KB)
- PNG (2400 px) (72 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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