23 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Oklahoma City | Cleveland County | 720,377 |
| Owasso | Tulsa County | 43,926 |
| Okmulgee | Okmulgee County | 11,370 |
| Okemah | Okfuskee County | 3,067 |
| Oakhurst | Tulsa County | 1,966 |
| Oologah | Rogers County | 1,364 |
| Okarche | Kingfisher County | 1,206 |
| Okeene | Blaine County | 1,045 |
| Oakland | Carter County | 933 |
| Oilton | Creek County | 893 |
| Okay | Wagoner County | 603 |
| Old Green | Adair County | 574 |
| Olustee | Jackson County | 457 |
| Ochelata | Washington County | 446 |
| Oktaha | Muskogee County | 348 |
| Optima | Texas County | 324 |
| Oaks | Delaware County | 268 |
| Oak Hill-Piney | Delaware County | 179 |
| Osage | Osage County | 178 |
| Orlando | Logan County | 141 |
| Olive | Creek County | 99 |
| Oakwood | Dewey County | 70 |
| Old Eucha | Delaware County | 20 |