19 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| DeForest | 1 | 11,279 | 10,848 | 0.77% | 1,299 | 8.68 | Village |
| Portage | 2 | 9,821 | 10,583 | -1.52% | 1,103 | 8.91 | City |
| Columbus | 3 | 5,386 | 5,540 | -0.57% | 1,187 | 4.54 | City |
| Lake Wisconsin | 4 | 5,060 | 4,573 | 1.16% | 378 | 13.40 | CDP |
| Prairie Sac | 5 | 4,336 | 4,421 | -0.39% | 2,245 | 1.93 | Village |
| Wisconsin Dells | 6 | 3,593 | 2,970 | 3.6% | 458 | 7.84 | City |
| Lodi | 7 | 3,199 | 3,199 | 0% | 1,847 | 1.73 | City |
| Poynette | 8 | 2,529 | 2,601 | -0.55% | 984 | 2.57 | Village |
| Pardeeville | 9 | 2,035 | 2,075 | -0.39% | 1,057 | 1.93 | Village |
| Fall River | 10 | 1,785 | 1,802 | -0.17% | 945 | 1.89 | Village |
| Randolph | 11 | 1,752 | 1,794 | -0.45% | 1,412 | 1.24 | Village |
| West Baraboo | 12 | 1,554 | 1,624 | -0.89% | 1,232 | 1.26 | Village |
| Rio | 13 | 1,135 | 1,124 | 0.18% | 905 | 1.25 | Village |
| Arlington | 14 | 826 | 846 | -0.48% | 797 | 1.04 | Village |
| Cambria | 15 | 762 | 772 | -0.26% | 776 | 0.98 | Village |
| Wyocena | 16 | 729 | 758 | -0.82% | 508 | 1.43 | Village |
| Friesland | 17 | 314 | 318 | -0.32% | 311 | 1.01 | Village |
| Doylestown | 18 | 271 | 278 | -0.37% | 70 | 3.88 | Village |
| Dekorra | 19 | 136 | 105 | 7.09% | 112 | 1.21 | CDP |
DeForest is the largest city in Columbia County, with a population of 11,279.
Dekorra is the smallest city in Columbia County.
There are 19 cities in Columbia County, Wisconsin.