| Odin Township, IL (Township) |
| Odon, IN (Town) |
| Odonnell, TX (City) |
| Odum, GA (City) |
| Oelrichs, SD (Town) |
| Oelwein, IA (City) |
| Offerle, KS (City) |
| Offerman, GA (City) |
| Ogallah, KS (Township) |
| Ogallala, NE (City) |
| Ogden, KS (City) |
| Ogden, UT (City) |
| Ogden, AR (City) |
| Ogden, KS (Township) |
| Ogden, NY (Town) |
