| City | County | 2026 Pop. ↓ |
|---|---|---|
| Northglenn | Adams County | 39,066 |
| New Castle | Garfield County | 4,907 |
| Niwot | Boulder County | 3,719 |
| Nederland | Boulder County | 1,466 |
| Nucla | Montrose County | 575 |
| Nunn | Weld County | 547 |
| Norwood | San Miguel County | 513 |
| North La Junta | Bent County | 512 |
| Naturita | Montrose County | 478 |
| No Name | Garfield County | 277 |
| North Washington | Adams County | 271 |
| Nathrop | Chaffee County | 137 |