7 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Johnstown | Weld County | 21,457 |
| Julesburg | Sedgwick County | 1,205 |
| Johnson Village | Chaffee County | 331 |
| Jansen | Las Animas County | 266 |
| Jamestown | Boulder County | 243 |
| Jackson Lake | Morgan County | 168 |
| Joes | Yuma County | 151 |