| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Waukesha | 1 | 70,894 | 71,149 | 0.03% | 2,778 | 26 | City |
| Menomonee Falls | 2 | 41,774 | 38,624 | 1.17% | 1,270 | 33 | Village |
| Brookfield | 3 | 41,364 | 41,479 | -0.2% | 1,514 | 27 | City |
| New Berlin | 4 | 39,883 | 40,446 | -0.18% | 1,095 | 36 | City |
| Muskego | 5 | 25,745 | 25,103 | 0.56% | 815 | 32 | City |
| Oconomowoc | 6 | 20,547 | 18,214 | 2.13% | 1,738 | 12 | City |
| Pewaukee | 7 | 16,486 | 15,945 | 0.68% | 844 | 20 | City |
| Sussex | 8 | 13,010 | 11,631 | 1.81% | 1,543 | 8 | Village |
| Hartland | 9 | 10,900 | 9,519 | 1.49% | 1,996 | 5 | Village |
| Mukwonago | 10 | 8,586 | 8,305 | 0.49% | 1,069 | 8 | Village |
| Waukesha | 11 | 8,526 | 8,461 | 0.22% | 414 | 21 | Village |
| Pewaukee | 12 | 8,210 | 8,221 | -0.07% | 1,993 | 4 | Village |
| Vernon | 13 | 7,465 | 7,474 | 0.01% | 249 | 30 | Village |
| Delafield | 14 | 7,329 | 7,189 | 0.21% | 779 | 9 | City |
| Elm Grove | 15 | 6,312 | 6,560 | -0.66% | 1,936 | 3 | Village |
| Summit | 16 | 5,445 | 4,831 | 2.29% | 264 | 21 | Village |
| Merton | 17 | 3,723 | 3,449 | 1.28% | 1,123 | 3 | Village |
| Wales | 18 | 2,895 | 2,862 | 0.35% | 898 | 3 | Village |
| Dousman | 19 | 2,692 | 2,433 | 1.01% | 904 | 3 | Village |
| Lannon | 20 | 2,211 | 1,419 | 7.49% | 894 | 2 | Village |
| North Prairie | 21 | 2,193 | 2,202 | 0% | 797 | 3 | Village |
| Eagle | 22 | 2,127 | 2,077 | 0.57% | 1,529 | 1 | Village |
| Butler | 23 | 1,747 | 1,784 | -0.29% | 2,234 | 1 | Village |
| Big Bend | 24 | 1,499 | 1,493 | 0.07% | 461 | 3 | Village |
| Nashotah | 25 | 1,295 | 1,318 | -0.23% | 796 | 2 | Village |
Waukesha is the largest city in Waukesha County, with a population of 70,894.
Nashotah is the smallest city in Waukesha County, with a population of 1,295.
There are 25 cities in Waukesha County, Wisconsin.