County outline
Where Winnebago County is located
Area breakdown
Land accounts for 75.1% of Winnebago County’s measured area and water for 24.9%. Its combined area converts to 1,498.5 square kilometers or approximately 370,285 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 434.697 | 1,125.86 | 278,206.1 |
| Water | 143.873 | 372.629 | 92,078.7 |
| Total | 578.57 | 1,498.489 | 370,284.8 |
How Winnebago County compares
By original Census land area, Winnebago County ranks #62 of 72 in Wisconsin and #2331 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.577 times the Wisconsin county-equivalent median of 753 square miles. It accounts for 0.8% of the combined county land area in the state.
See the complete Wisconsin ranking · What counts as a county equivalent?
Population and density of Winnebago County
The Census Bureau estimates that 174,218 people lived in Winnebago County on July 1, 2025. That ranks #407 of 3,222 county equivalents nationally and #7 of 72 in Wisconsin. Since the April 1, 2020 estimates base of 171,740, the population has grown by 2,478 (+1.4%), compared with +1.3% for Wisconsin as a whole.
With 434.7 square miles of land, that is 401 people per square mile (155 per km²), placing Winnebago County #407 nationally for density and #8 in Wisconsin. The median county equivalent has 47 people per square mile; the Wisconsin median is 51. Put another way, there are about 1.6 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 171,833 | 170,651 | 170,984 | 172,118 | 173,294 | 174,218 |
| Change | — | −1,182 | +333 | +1,134 | +1,176 | +924 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Winnebago County
Winnebago County is divided into 22 cities and towns. In Wisconsin, county subdivisions are local governments, and together they cover all of the county’s land and residents.
The most populous is Oshkosh city, with 67,460 residents (38.7% of the county). The largest by land is Clayton town, at 36.2 mi², or 8.3% of the county’s land. Among those with at least 1,000 residents in 2020, Clayton town grew fastest since then (+22.3%).
| County subdivision | Population 2025 | Since 2020 | Land mi² | Share of county land |
|---|---|---|---|---|
| Oshkosh cityCounty seat | 67,460 | +0.8% | 27.8 | 6.4% |
| Neenah city | 27,638 | +1.1% | 9.671 | 2.2% |
| Fox Crossing village | 19,320 | +1.8% | 12.6 | 2.9% |
| Menasha city | 15,153 | −0.7% | 4.511 | 1% |
| Algoma town | 6,956 | +2.6% | 7.465 | 1.7% |
| Clayton town | 5,303 | +22.3% | 36.2 | 8.3% |
| Neenah town | 3,673 | −0.8% | 7.318 | 1.7% |
| Omro city | 3,639 | −0.5% | 2.448 | 0.6% |
| Winneconne town | 2,681 | +2.8% | 21.6 | 5% |
| Winneconne village | 2,498 | −1.3% | 1.483 | 0.3% |
| Black Wolf town | 2,447 | +0.9% | 15.5 | 3.6% |
| Oshkosh townCounty seat | 2,436 | −0% | 9.23 | 2.1% |
| Omro town | 2,409 | +5.2% | 32.4 | 7.5% |
| Winchester town | 1,811 | +1% | 35.5 | 8.2% |
| Vinland town | 1,739 | −1.6% | 28.3 | 6.5% |
Show the other 7 subdivisions
| Name | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Rushford town | 1,690 | +4.2% | 34.9 |
| Appleton city | 1,414 | −1.3% | 0.404 |
| Utica town | 1,375 | +1% | 35.5 |
| Nekimi town | 1,335 | −0.4% | 28.3 |
| Poygan town | 1,297 | +3.2% | 23.1 |
| Wolf River town | 1,226 | +1.8% | 28.8 |
| Nepeuskun town | 718 | −1% | 31.6 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Winnebago County. Land: 2026 Census Gazetteer. How communities are listed.
Metropolitan area
Winnebago County is a central county of the Oshkosh-Neenah, WI Metropolitan Statistical Area. Winnebago County is the area’s only county equivalent, so the metro area has the same 434.7 square miles of land. By combined land it ranks #371 of 393 metropolitan areas, and #259 by population. It belongs to the Appleton-Oshkosh-Neenah, WI Combined Statistical Area.
ZIP codes
18 ZIP Code Tabulation Areas have land in Winnebago County; 11 of them have most of their land inside the county, and the others mainly cover neighboring areas.
549015490254904549145491554923549275494054947549525495654963549645497154979549805498554986
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Winnebago County
Winnebago County shares a land border with 6 county equivalents. It has more land than 2 of them. The largest neighbor is Waupaca County (747.7 mi²) and the smallest is Calumet County (318.3 mi²). Together with its neighbors, Winnebago County forms a block of 3,833.5 mi² of land, of which it holds 11.3%.
| Bordering county equivalent | Land mi² | Size vs. Winnebago | Compare |
|---|---|---|---|
| Waupaca County | 747.7 | 1.7× larger | Compare |
| Fond du Lac County | 719.6 | 1.7× larger | Compare |
| Outagamie County | 637.6 | 1.5× larger | Compare |
| Waushara County | 626.2 | 1.4× larger | Compare |
| Green Lake County | 349.5 | 1.2× smaller | Compare |
| Calumet County | 318.3 | 1.4× smaller | Compare |
How big is Winnebago County compared with U.S. states?
Winnebago County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.4 times as much. Wisconsin’s county land could hold about 125 areas the size of Winnebago County.
Another way to picture it: the same land area would fill a square about 20.8 miles (33.6 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Winnebago County?
Winnebago County has more land than 891 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Winnebago County at #1,842 nationally by total area, 489 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.
Its water share is 24.9%, compared with a national county-equivalent median of 1.2% — 23.7 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Winnebago County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2330 | Watonwan County, Minnesota | 435 | Compare |
| #2331 | Winnebago County, Wisconsin | 434.7 | This county |
| #2332 | Beaver County, Pennsylvania | 434.7 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 44.085707, -88.668149. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 1,125,861,120 m²; AWATER: 372,630,371 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Winnebago County?
Winnebago County, Wisconsin has 434.7 square miles (1,125.9 km²) of land and 143.9 square miles of water, for a total area of 578.6 square miles. It ranks #2331 of 3,222 U.S. county equivalents by land area.
Is Winnebago County the largest county in Wisconsin?
No. Winnebago County ranks #62 of 72 in Wisconsin by land area. The largest is Marathon County, with 1,545.2 square miles of land.
What counties border Winnebago County?
Winnebago County shares a land border with Fond du Lac County, Calumet County, Waushara County, Outagamie County, Waupaca County, and Green Lake County.
What is the population of Winnebago County?
The Census Bureau estimates Winnebago County had 174,218 residents on July 1, 2025, ranking #407 of 3,222 county equivalents. That is 401 people per square mile of land.
What is the county seat of Winnebago County?
The county seat of Winnebago County is Oshkosh.
What cities and towns are in Winnebago County?
Winnebago County has 22 county subdivisions (cities, towns and townships). The most populous five are Oshkosh city, Neenah city, Fox Crossing village, Menasha city, and Algoma town.
Is Winnebago County part of a metropolitan area?
Yes. It is a central county of the Oshkosh-Neenah, WI Metropolitan Statistical Area.
How many ZIP codes are in Winnebago County?
18 ZIP Code Tabulation Areas have land in Winnebago County, and 11 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Winnebago County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2.4 times as much land.
How many acres of land are in Winnebago County?
The land measurement converts to approximately 278,206 acres. Including water, total area is approximately 370,285 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.