| Abbreviation | Definition |
|---|---|
| ORSD | Ouachita River School District |
| OSA | Oakland School for the Arts |
| OSA | Old School Arcade |
| OSAA | Oregon School Activities Association |
| OSAF | Online School Activity Funds |
| OSAT | One School At a Time |
| OSB | Oklahoma School for the Blind |
| OSBA | Ohio School Boards Association |
| OSBL | Old School Baseball League |
| OSCAR | Ohio School Counselor Accountability Report |
| OSCAR | Out of School Care At the Ridge |
| OSCARS | Out of School Care and Recreation Service |
| OSCC | Ogilvie School Community Council |
| OSD | Ogden School District |
| OSD | Ohio School for the Deaf |
| OSD | Oklahoma School for the Deaf |
| OSD | Olympia School District |
| OSD | Opportunity School District |
| OSD | Oregon School District |
| OSD | Oregon School for the Deaf |