23 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Oklahoma City | Cleveland County | 715,893 |
| Owasso | Tulsa County | 43,007 |
| Okmulgee | Okmulgee County | 11,433 |
| Okemah | Okfuskee County | 3,046 |
| Oakhurst | Tulsa County | 1,966 |
| Oologah | Rogers County | 1,361 |
| Okarche | Kingfisher County | 1,198 |
| Okeene | Blaine County | 1,025 |
| Oakland | Carter County | 928 |
| Oilton | Creek County | 894 |
| Okay | Wagoner County | 606 |
| Old Green | Adair County | 574 |
| Olustee | Jackson County | 462 |
| Ochelata | Washington County | 444 |
| Oktaha | Muskogee County | 351 |
| Optima | Texas County | 313 |
| Oaks | Delaware County | 275 |
| Oak Hill-Piney | Delaware County | 179 |
| Osage | Osage County | 178 |
| Orlando | Logan County | 143 |
| Olive | Creek County | 99 |
| Oakwood | Dewey County | 67 |
| Old Eucha | Delaware County | 20 |