18 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Rifle | Garfield County | 10,718 |
| Roxborough Park | Douglas County | 9,046 |
| Redlands | Mesa County | 8,971 |
| Rocky Ford | Otero County | 3,760 |
| Rangely | Rio Blanco County | 2,286 |
| Ridgway | Ouray County | 1,306 |
| Rockvale | Fremont County | 538 |
| Red Feather Lakes | Larimer County | 449 |
| Redvale | Montrose County | 377 |
| Rico | Dolores County | 346 |
| Romeo | Conejos County | 313 |
| Red Cliff | Eagle County | 236 |
| Redstone | Eagle County | 220 |
| Rye | Pueblo County | 202 |
| Rollinsville | Gilpin County | 191 |
| Rock Creek Park | El Paso County | 176 |
| Raymer (New Raymer) | Morgan County | 110 |
| Ramah | El Paso County | 104 |