| Abbreviation | Definition |
|---|---|
| OMSG | Oxford Medical School Gazette |
| ONPS | Old Noarlunga Primary School |
| ONSA | Online Notice of School Assignment |
| OOHS | Our Own High School |
| OOMS | Olentangy Orange Middle School |
| OOOPS | Ossington Old Orchard Public School |
| OOS | Out Of School |
| OOSS | Out Of School Suspension |
| OP | Off Premises |
| OP | Ontario Public |
| OPES | Oak Point Elementary School |
| OPES | Oak Pointe Elementary School |
| OPES | Orchard Park Elementary School |
| OPHS | Oak Park High School |
| OPHS | Orchard Park High School |
| OPHS | Osbourn Park High School |
| OPHS | Ouachita Parish High School |
| OPII | Omaha Private Instruction Institute |
| OPMS | Olive Peirce Middle School |
| OPS | Omaha Public Schools |