24 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Omaha | Douglas County | 488,385 |
| Offutt AFB | Sarpy County | 5,873 |
| Ogallala | Keith County | 4,721 |
| O'Neill | Holt County | 3,579 |
| Ord | Valley County | 2,085 |
| Oakland | Burt County | 1,350 |
| Osceola | Polk County | 888 |
| Osmond | Pierce County | 802 |
| Oshkosh | Garden County | 755 |
| Oxford | Furnas County | 687 |
| Overton | Dawson County | 591 |
| Orchard | Antelope County | 348 |
| Orleans | Harlan County | 323 |
| Oakdale | Antelope County | 271 |
| Odell | Gage County | 255 |
| Overland | Hamilton County | 204 |
| Otoe | Otoe County | 172 |
| Oconto | Custer County | 141 |
| Odessa | Buffalo County | 129 |
| Ohiowa | Fillmore County | 121 |
| Octavia | Butler County | 108 |
| Oak | Nuckolls County | 52 |
| Ong | Clay County | 51 |
| Obert | Cedar County | 20 |