24 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Fort Collins | Larimer County | 171,391 |
| Fountain | El Paso County | 29,242 |
| Four Square Mile | Arapahoe County | 26,816 |
| Firestone | Weld County | 20,762 |
| Frederick | Weld County | 19,544 |
| Fort Carson | El Paso County | 19,516 |
| Fruita | Mesa County | 14,156 |
| Federal Heights | Adams County | 13,759 |
| Fort Morgan | Morgan County | 11,975 |
| Fairmount | Adams County | 11,205 |
| Fort Lupton | Weld County | 10,918 |
| Fruitvale | Mesa County | 8,073 |
| Florence | Fremont County | 3,902 |
| Frisco | Summit County | 2,637 |
| Fraser | Grand County | 1,575 |
| Fowler | Otero County | 1,176 |
| Floyd Hill | Clear Creek County | 816 |
| Fairplay | Park County | 765 |
| Foxfield | Arapahoe County | 739 |
| Flagler | Kit Carson County | 594 |
| Fort Garland | Costilla County | 424 |
| Fleming | Logan County | 418 |
| Franktown | Douglas County | 407 |
| Florissant | Teller County | 168 |