| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Silverthorne | 1 | 5,645 | 4,462 | 4.19% | 1,390 | 4 | Town |
| Breckenridge | 2 | 5,008 | 5,054 | -0.14% | 829 | 6 | Town |
| Frisco | 3 | 2,763 | 2,926 | -1.04% | 1,654 | 2 | Town |
| Keystone | 4 | 1,269 | 1,295 | 13.71% | 695 | 2 | Town |
| Keystone | 5 | 1,269 | 1,295 | -0.39% | 695 | 2 | Town |
| Keystone | 6 | 1,118 | 1,295 | 0.18% | 612 | 2 | Town |
| Keystone | 7 | 1,118 | 1,295 | -12.24% | 612 | 2 | Town |
| Dillon | 8 | 1,023 | 1,061 | -0.58% | 689 | 1 | Town |
| Blue River | 9 | 856 | 872 | -0.35% | 352 | 2 | Town |
| Montezuma | 10 | 71 | 75 | -1.39% | 899 | 0 | Town |
Silverthorne is the largest city in Summit County, with a population of 5,645.
Montezuma is the smallest city in Summit County, with a population of 71.
There are 10 cities in Summit County, Colorado.