| Osnabrock, ND (Township) |
| Osnabrock, ND (City) |
| Osnaburg Township, OH (Township) |
| Osolo, IN (Township) |
| Osprey Oaks Community Development District, FL (CDD) |
| Osseo, MN (City) |
| Osseo, WI (City) |
| Ossian, IN (Town) |
| Ossian, IA (City) |
| Ossian, NY (Town) |
| Ossineke Township, MI (Township) |
| Ossining, NY (Town) |
| Ossining, NY (Village) |
| Ossipee, NC (Town) |
| Ossipee, NH (Town) |
