| Abbreviation | Definition |
|---|---|
| OSHS | Olathe South High School |
| OSHS | Oliver Springs High School |
| OSM | Old School Musical |
| OSME | Orissa School of Mining Engineering, |
| OSMS | Ocean Springs Middle School |
| OSMS | Ocean State Montessori School |
| OSMS | Old Saybrook Middle School |
| OSMS | Oliver Springs Middle School |
| OSMS | Online School Management System |
| OSMS | Online School Management Systems |
| OSMS | Otto Shortell Middle School |
| OSN | Old School Nintendo |
| OSOB | One School One Book |
| OSOF | Our Schools Our Future |
| OSOO | One School One Operator |
| OSOS | Open Schools for Open Societies |
| OSP | Old School Players |
| OSP | Online School Payments |
| OSPA | Office of School Performance and Accountability |
| OSPA | Oregon School |