| Okfuskee County, OK (County) |
| Oklahoma, OK (State) |
| Oklahoma, PA (Borough) |
| Oklahoma City, OK (City) |
| Oklahoma County, OK (County) |
| Oklee, MN (City) |
| Okmulgee, OK (City) |
| Okmulgee County, OK (County) |
| Okoboji, IA (City) |
| Okoboji Township, IA (Township) |
| Okolona, AR (Town) |
| Okolona, MS (City) |
| Oktaha, OK (Town) |
| Oktibbeha County, MS (County) |
| Ola, AR (City) |
