| Onaway Area Community School District, MI (District) |
| One City Preparatory Academy, WI (PSA) |
| One City Schools Inc, WI (PSA) |
| One City Senior Preschool, WI (PSA) |
| Oneida, TN (District) |
| Oneida, WI (ISD) |
| Oneida City School District, NY (District) |
| Oneida County, ID (ISD) |
| Oneida County, NY (ISD) |
| Oneida County District, ID (District) |
| Oneida Township S/D #3, MI (District) |
| Oneida-Herkimer-Madison Boces, NY (ISD) |
| Onekama Consolidated Schools, MI (District) |
| Oneonta City, AL (District) |
| Oneonta City School District, NY (District) |
