8 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Oro Valley | Pima County | 49,669 |
| Oracle | Pinal County | 3,031 |
| Oak Creek Canyon | Coconino County | 395 |
| Orange Grove Mobile Manor | Yuma County | 145 |
| Oatman | Mohave County | 89 |
| Oxbow Estates | Gila County | 50 |
| Oljato-Monument Valley | Navajo County | 37 |
| Oak Springs | Apache County | 34 |