23 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Oklahoma City | Cleveland County | 727,836 |
| Owasso | Tulsa County | 45,031 |
| Okmulgee | Okmulgee County | 11,386 |
| Okemah | Okfuskee County | 3,068 |
| Oakhurst | Tulsa County | 1,920 |
| Oologah | Rogers County | 1,378 |
| Okarche | Kingfisher County | 1,219 |
| Okeene | Blaine County | 1,039 |
| Oakland | Carter County | 951 |
| Oilton | Creek County | 895 |
| Okay | Wagoner County | 622 |
| Olustee | Jackson County | 456 |
| Old Green | Adair County | 453 |
| Ochelata | Washington County | 450 |
| Oktaha | Muskogee County | 350 |
| Optima | Texas County | 322 |
| Oaks | Delaware County | 268 |
| Osage | Osage County | 179 |
| Orlando | Logan County | 143 |
| Oak Hill-Piney | Delaware County | 124 |
| Olive | Creek County | 114 |
| Oakwood | Dewey County | 69 |
| Old Eucha | Delaware County | 36 |