Ozaukee County area

Population and density of Ozaukee County

The Census Bureau estimates that 94,346 people lived in Ozaukee County on July 1, 2025. That ranks #657 of 3,222 county equivalents nationally and #18 of 72 in Wisconsin. Since the April 1, 2020 estimates base of 91,504, the population has grown by 2,842 (+3.1%), compared with +1.3% for Wisconsin as a whole.

With 233 square miles of land, that is 405 people per square mile (156 per km²), placing Ozaukee County #405 nationally for density and #7 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.

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 Ozaukee County

Ozaukee County is divided into 16 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 Mequon city, with 25,120 residents (26.6% of the county), and it is also the largest by land at 46.3 mi². The county seat, Port Washington city, has 12,658 residents. Among those with at least 1,000 residents in 2020, Grafton village grew fastest since then (+10.9%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Ozaukee County. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

Ozaukee County is an outlying county of the Milwaukee-Waukesha, WI Metropolitan Statistical Area. Its 4 county equivalents have 1,575,010 residents on 1,454.8 square miles of land; Ozaukee County accounts for 16% of the land and 6% of the residents. By combined land it ranks #225 of 393 metropolitan areas, and #42 by population. It belongs to the Milwaukee-Racine-Waukesha, WI Combined Statistical Area.

ZIP codes

13 ZIP Code Tabulation Areas have land in Ozaukee County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.

53004530125301353021530245307453075530805309053092530955309753217

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 Ozaukee County

Ozaukee County shares a land border with 3 county equivalents. Each of them has more land than Ozaukee County. The largest neighbor is Sheboygan County (511.5 mi²) and the smallest is Milwaukee County (241.5 mi²). Together with its neighbors, Ozaukee County forms a block of 1,416.6 mi² of land, of which it holds 16.4%.

How big is Ozaukee County compared with U.S. states?

Ozaukee County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 4.4 times as much. Wisconsin’s county land could hold about 232 areas the size of Ozaukee County.

Another way to picture it: the same land area would fill a square about 15.3 miles (24.6 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 Ozaukee County?

Ozaukee County has more land than 279 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 Ozaukee County at #657 nationally by total area, 2,286 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 79.1%, compared with a national county-equivalent median of 1.2% — 78 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 Ozaukee County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

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.