| Osceola School District, WI (District) |
| Osceola School District, AR (District) |
| Oscoda Area Schools, MI (District) |
| Oshki Ogimaag Charter School, MN (District) |
| Oshkosh Area School District, WI (District) |
| Oskaloosa Comm School District, IA (District) |
| Oskaloosa Public Schools, KS (District) |
| 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) |
