O
| Name of place | Number of counties | Principal county | Lower zip code | Upper zip code |
|---|---|---|---|---|
| Oakley | 1 | Cassia County | 83346 | |
| Obsidian | 1 | Custer County | 83340 | |
| Oden | 1 | Bonner County | ||
| Ola | 1 | Gem County | 83657 | |
| Old Beaver | 1 | Clark County | ||
| Old Fort | 1 | Valley County | ||
| Old Golden | 1 | Idaho County | ||
| Oldtown | 1 | Bonner County | 83822 | |
| Olsen | 1 | Bingham County | ||
| Omega | 1 | Benewah County | ||
| Omill | 1 | Clearwater County | ||
| Onaway | 1 | Latah County | 83855 | |
| Orchard | 1 | Ada County | 83707 | |
| Orchard Station | 1 | Ada County | 83704 | |
| Oreana | 1 | Owyhee County | 83650 | |
| Orofino | 1 | Clearwater County | 83544 | |
| Orogrande | 1 | Idaho County | 83525 | |
| Orvin | 1 | Bonneville County | ||
| Osburn | 1 | Shoshone County | 83849 | |
| Osgood | 1 | Bonneville County | 83401 | |
| Outlet Bay | 1 | Bonner County | ||
| Ovid | 1 | Bear Lake County | 83260 | |
| Owinza | 1 | Lincoln County | ||
| Owyhee | 1 | Ada County | ||
| Owyhee Heights | 1 | Owyhee County | ||
| Oxford | 1 | Franklin County | 83263 |
Read more about this topic: List Of Places In Idaho: L-Z