City | 2024 Population |
|---|---|
| O'Neill | 3,576 |
| Oak | 52 |
| Oak Creek | 538 |
| Oakdale | 269 |
| Oakland | 1,354 |
| Obert | 22 |
| Oconee | 487 |
| Oconto | 140 |
| Octavia | 108 |
| Odell | 255 |
| Odessa | 201 |
| Offutt AFB | 5,974 |
| Ogallala | 4,616 |
| Ohiowa | 122 |
| Olive | 215 |
| Omaha | 480,194 |
| Oneida | 456 |
| Ong | 49 |
| Orchard | 352 |
| Ord | 2,066 |
| Orleans | 330 |
| Osceola | 872 |
| Oshkosh | 754 |
| Osmond | 796 |
| Otoe | 167 |
| Ottercreek | 200 |
| Overland | 136 |
| Overton | 586 |
| Oxford | 696 |