17 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| DeForest | 1 | 12,980 | 10,819 | 2.85% | 1,366 | 10 | Village |
| Portage | 2 | 9,670 | 10,585 | -1.55% | 1,086 | 9 | City |
| Columbus | 3 | 5,378 | 5,531 | -0.46% | 1,185 | 5 | City |
| Prairie du Sac | 4 | 4,325 | 4,423 | -0.37% | 2,170 | 2 | Village |
| Wisconsin Dells | 5 | 3,227 | 3,016 | 1.1% | 412 | 8 | City |
| Lodi | 6 | 3,202 | 3,195 | 0.03% | 1,849 | 2 | City |
| Poynette | 7 | 2,951 | 2,600 | 2.04% | 1,149 | 3 | Village |
| Pardeeville | 8 | 2,351 | 2,072 | 2.04% | 1,221 | 2 | Village |
| Fall River | 9 | 1,852 | 1,854 | 0% | 981 | 2 | Village |
| Randolph | 10 | 1,744 | 1,797 | -0.51% | 1,405 | 1 | Village |
| West Baraboo | 11 | 1,565 | 1,628 | -0.63% | 1,241 | 1 | Village |
| Rio | 12 | 1,126 | 1,126 | 0% | 898 | 1 | Village |
| Arlington | 13 | 820 | 849 | -0.61% | 791 | 1 | Village |
| Cambria | 14 | 765 | 773 | -0.13% | 779 | 1 | Village |
| Wyocena | 15 | 718 | 760 | -0.97% | 501 | 1 | Village |
| Friesland | 16 | 311 | 316 | -0.32% | 308 | 1 | Village |
| Doylestown | 17 | 272 | 278 | -0.37% | 70 | 4 | Village |
DeForest is the largest city in Columbia County, with a population of 12,980.
Doylestown is the smallest city in Columbia County, with a population of 272.
There are 17 cities in Columbia County, Wisconsin.