County facts · Land area · October 21, 2026
Largest Counties in Wisconsin by Area and Population
The largest Wisconsin counties by land area and by 2023 population, plus the smallest, county seats and a link to each official parcel map.
Looking for the largest counties in Wisconsin? Wisconsin has 72 counties covering about 54,167 square miles of land, based on the Census Bureau's 2020 Gazetteer. The largest by land area is Marathon County, at about 1,545 square miles, roughly 6.7 times the size of the smallest, Pepin County (232 sq mi). Measured by people instead, the largest is Milwaukee County, with about 916,205 residents in the Census Bureau's July 1, 2023 estimate.
The tables below rank the counties both ways. Each row links to the county's Platbookmapper page and straight to its official parcel viewer.
Wisconsin counties at a glance
- Counties: 72
- Land area: about 54,167 sq mi, plus about 11,330 sq mi of water inside county lines
- Residents, 2023 estimates: about 5,910,955, or about 109 people per square mile of land
- Median county land area: about 753 sq mi
- With a verified public parcel viewer in our directory: 72 of 72 (1 of them through a statewide viewer)
The 10 largest Wisconsin counties by land area
| # | County | Seat | Land (sq mi) | 2023 pop. | People per sq mi | Parcel viewer |
|---|---|---|---|---|---|---|
| 1 | Marathon County | Wausau | 1,545 | 138,612 | 90 | county web map |
| 2 | Bayfield County | Washburn | 1,478 | 16,769 | 11 | county web map |
| 3 | Marinette County | Marinette | 1,399 | 42,106 | 30 | county web map |
| 4 | Douglas County | Superior | 1,304 | 44,264 | 34 | WinGIS Xtreme |
| 5 | Sawyer County | Hayward | 1,258 | 18,552 | 15 | Beacon (Schneider Geospatial) |
| 6 | Price County | Phillips | 1,254 | 14,102 | 11 | WinGIS Xtreme |
| 7 | Clark County | Neillsville | 1,210 | 34,774 | 29 | WinGIS Xtreme |
| 8 | Dane County | Madison | 1,196 | 575,347 | 481 | county web map |
| 9 | Grant County | Lancaster | 1,147 | 51,409 | 45 | ArcGIS |
| 10 | Oneida County | Rhinelander | 1,114 | 38,226 | 34 | county web map |
Together these 10 cover about 24% of Wisconsin's land area and hold about 16% of its residents.
The 10 most populous Wisconsin counties
| # | County | Seat | 2023 pop. | Land (sq mi) | Parcel viewer |
|---|---|---|---|---|---|
| 1 | Milwaukee County | Milwaukee | 916,205 | 241 | county web map |
| 2 | Dane County | Madison | 575,347 | 1,196 | county web map |
| 3 | Waukesha County | Waukesha | 412,591 | 550 | county web map |
| 4 | Brown County | Green Bay | 271,417 | 530 | ArcGIS Web AppBuilder |
| 5 | Racine County | Racine | 196,613 | 333 | ArcGIS Experience Builder |
| 6 | Outagamie County | Appleton | 193,234 | 638 | ArcGIS Experience Builder |
| 7 | Winnebago County | Oshkosh | 171,735 | 435 | county web map |
| 8 | Kenosha County | Kenosha | 167,488 | 272 | county web map |
| 9 | Rock County | Janesville | 164,278 | 718 | ArcGIS Instant Apps |
| 10 | Marathon County | Wausau | 138,612 | 1,545 | county web map |
These 10 hold about 54% of Wisconsin's residents in the 2023 estimates.
The 5 smallest Wisconsin counties by land area
| County | Seat | Land (sq mi) | 2023 pop. | Parcel viewer |
|---|---|---|---|---|
| Pepin County | Durand | 232 | 7,441 | WinGIS Xtreme |
| Ozaukee County | Port Washington | 233 | 93,460 | county web map |
| Milwaukee County | Milwaukee | 241 | 916,205 | county web map |
| Kenosha County | Kenosha | 272 | 167,488 | county web map |
| Calumet County | Chilton | 318 | 53,199 | WinGIS Xtreme |
Most and least crowded
- Most people per square mile: Milwaukee County, about 3,794 (then Waukesha County, 751, and Kenosha County, 616)
- Fewest people per square mile: Iron County, about 8.2 (then Forest County, 9.2, and Florence County, 9.6)
Counties with the most water
The Census Bureau reports water separately from land. It counts lakes, reservoirs, rivers and, for coastal and Great Lakes counties, the water inside the county boundary.
- Door County: about 1,888 sq mi of water, 80% of its total area
- Ashland County: about 1,247 sq mi of water, 54% of its total area
- Milwaukee County: about 948 sq mi of water, 80% of its total area
Using these numbers in a land search
- Land area is not parcel count. A large rural county can hold fewer parcels than a small suburban one, so size alone says little about how busy its parcel map is.
- Search, don't scroll. In a big county, type an address, owner name or parcel number into the viewer's search box, where it has one, instead of panning across the map.
- Records follow the county line. Deeds, plats and tax bills are kept by the county where the parcel sits, so a tract that crosses a county line usually has a parcel number in each county.
- Rounded figures. Land and water areas are rounded to whole square miles. People per square mile is the 2023 estimate divided by land area.
Related guides
- Wisconsin county GIS websites by viewer
- Wisconsin statewide parcel map
- Wisconsin landowner maps for hunting
- Illinois–Wisconsin border counties
- Michigan–Wisconsin border counties
- Minnesota–Wisconsin border counties
More: All Wisconsin counties on Platbookmapper
Sources
- U.S. Census Bureau Gazetteer files, 2020 county land and water area.
- U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2023 (July 1, 2023 estimates)
- Platbookmapper county GIS directory (live data file behind our county pages, pulled October 21, 2026) for each county's official parcel viewer.
- County seats: Wikidata (county seat property), cross-checked against Census place names.