8 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Mequon | 1 | 25,425 | 25,136 | 0.19% | 549 | 46 | City |
| Cedarburg | 2 | 13,416 | 12,201 | 1.54% | 2,726 | 5 | City |
| Grafton | 3 | 13,068 | 12,087 | 1.27% | 2,495 | 5 | Village |
| Port Washington | 4 | 12,907 | 12,435 | 0.62% | 2,168 | 6 | City |
| Saukville | 5 | 4,331 | 4,252 | 0.3% | 1,223 | 4 | Village |
| Thiensville | 6 | 3,306 | 3,285 | 0.12% | 3,185 | 1 | Village |
| Belgium | 7 | 2,556 | 2,432 | 0.83% | 1,189 | 2 | Village |
| Fredonia | 8 | 2,285 | 2,273 | 0.09% | 1,022 | 2 | Village |
Mequon is the largest city in Ozaukee County, with a population of 25,425.
Fredonia is the smallest city in Ozaukee County, with a population of 2,285.
There are 8 cities in Ozaukee County, Wisconsin.