8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Silverthorne | 1 | 5,412 | 4,451 | 3.68% | 1,333 | 4 | Town |
| Breckenridge | 2 | 4,851 | 5,056 | -0.84% | 803 | 6 | Town |
| Frisco | 3 | 2,684 | 2,922 | -1.76% | 1,607 | 2 | Town |
| Dillon | 4 | 1,000 | 1,065 | -1.28% | 673 | 1 | Town |
| Keystone | 5 | 974 | 799 | -0.71% | 24 | 41 | CDP |
| Blue River | 6 | 827 | 870 | -1.08% | 340 | 2 | Town |
| Copper Mountain | 7 | 260 | 455 | -2.99% | 8 | 32 | CDP |
| Montezuma | 8 | 70 | 75 | -1.41% | 886 | 0 | Town |
Silverthorne is the largest city in Summit County, with a population of 5,412.
Montezuma is the smallest city in Summit County, with a population of 70.
There are 8 cities in Summit County, Colorado.