| Osmond Community Schools, NE (District) |
| Osnaburg Local School District, OH (District) |
| Osseo Public School District, MN (District) |
| Osseo-Fairchild School District, WI (District) |
| Ossining Union Free School District, NY (District) |
| Oswayo Valley SD, PA (District) |
| Oswego, KS (District) |
| Oswego Boces, NY (ISD) |
| Oswego City School District, NY (District) |
| Oswego County, NY (ISD) |
| Otego-unadilla Central School District, NY (District) |
| Otero County, NM (ISD) |
| Otero County, CO (ISD) |
| Othello School District, WA (District) |
| Otis R-3, CO (District) |
