8 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Oro Valley | Pima County | 49,037 |
| Oracle | Pinal County | 3,011 |
| Oak Creek Canyon | Coconino County | 327 |
| Oatman | Mohave County | 84 |
| Oxbow Estates | Gila County | 83 |
| Orange Grove Mobile Manor | Yuma County | 58 |
| Oljato-Monument Valley | Navajo County | 53 |
| Oak Springs | Apache County | 41 |