City | 2024 Population |
|---|---|
| O'Neill | 3,535 |
| Oak | 50 |
| Oak Creek | 538 |
| Oakdale | 268 |
| Oakland | 1,365 |
| Obert | 23 |
| Oconee | 487 |
| Oconto | 139 |
| Octavia | 110 |
| Odell | 251 |
| Odessa | 201 |
| Offutt AFB | 5,974 |
| Ogallala | 4,722 |
| Ohiowa | 119 |
| Olive | 215 |
| Omaha | 477,705 |
| Oneida | 456 |
| Ong | 49 |
| Orchard | 349 |
| Ord | 2,114 |
| Orleans | 329 |
| Osceola | 839 |
| Oshkosh | 764 |
| Osmond | 815 |
| Otoe | 168 |
| Ottercreek | 200 |
| Overland | 136 |
| Overton | 573 |
| Oxford | 706 |