| Oklahoma |
| Oakhurst | Okay | Olustee | Oscar |
| Oaks | Okeene | Omega | Overbrook |
| Oakwood | Okemah | Oologah | Owasso |
| Ochelata | Oklahoma City | Optima | |
| Oilton | Okmulgee | Orlando | |
| Okarche | Oktaha | Osage |
| Popular towns & cities |
| Ada | Durant | Muskogee | Shawnee |
| Ardmore | Edmond | Norman | Stillwater |
| Bartlesville | Enid | Oklahoma City | Tahlequah |
| Broken Arrow | Lawton | Owasso | Tulsa |
| Claremore | Mcalester | Ponca City | Yukon |
