24 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Omaha | Douglas County | 477,053 |
| Offutt AFB | Sarpy County | 5,873 |
| Ogallala | Keith County | 4,553 |
| O'Neill | Holt County | 3,577 |
| Ord | Valley County | 2,054 |
| Oakland | Burt County | 1,350 |
| Osceola | Polk County | 873 |
| Osmond | Pierce County | 796 |
| Oshkosh | Garden County | 738 |
| Oxford | Furnas County | 691 |
| Overton | Dawson County | 581 |
| Orchard | Antelope County | 350 |
| Orleans | Harlan County | 327 |
| Oakdale | Antelope County | 268 |
| Odell | Gage County | 253 |
| Overland | Hamilton County | 204 |
| Otoe | Otoe County | 168 |
| Oconto | Custer County | 140 |
| Odessa | Buffalo County | 129 |
| Ohiowa | Fillmore County | 122 |
| Octavia | Butler County | 108 |
| Oak | Nuckolls County | 52 |
| Ong | Clay County | 49 |
| Obert | Cedar County | 22 |