| Abbreviation | Definition |
|---|---|
| OPEP | Ontario Pesticide Education Program |
| OPEP | Organization of Parent Education Programs |
| OPEP | Organization of Parenting Education Programs |
| OPET | Office for Professional Education and Technology |
| OPF | Overseas Pakistani Foundation |
| OPI | Office of Public Instruction |
| OPKL | Orientasi Pengembangan Kemampuan Lapangan |
| OPLC | Octorara Primary Learning Center |
| OPLE | Observation Protocol for Learning Environments |
| OPP | OPPosite |
| OPPE | Office of Professional Pharmacy Education |
| OPPER | Office of Program Planning and Educational Research |
| OPR | Old Parochial Registers |
| OPSA | Owens Park Students Association |
| OPSBA | Ontario Public School Boards' Association |
| OPSHACOM | Opinion, Shape, Age, Color, Origin, and Material |
| OPT | Observation Participation And Teaching |
| OPT | Ohio Proficiency Test |
| OPT | Optional Practical Training |
| OPT | Organization Of Parents And Teachers |