8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Silverthorne | 1 | 5,263 | 4,455 | 3.18% | 1,296 | 4.06 | Town |
| Breckenridge | 2 | 4,863 | 5,055 | -0.78% | 805 | 6.04 | Town |
| Frisco | 3 | 2,655 | 2,924 | -1.99% | 1,590 | 1.67 | Town |
| Dillon | 4 | 983 | 1,065 | -1.6% | 662 | 1.49 | Town |
| Keystone | 5 | 974 | 799 | -0.71% | 24 | 41.40 | CDP |
| Blue River | 6 | 836 | 876 | -0.95% | 343 | 2.43 | Town |
| Copper Mountain | 7 | 260 | 455 | -2.99% | 8 | 32.06 | CDP |
| Montezuma | 8 | 69 | 76 | -1.43% | 873 | 0.08 | Town |
Silverthorne is the largest city in Summit County, with a population of 5,263.
Montezuma is the smallest city in Summit County.
There are 8 cities in Summit County, Colorado.