| Acronym | Definition |
|---|
| OPEP | Organización de Países Exportadores de Petróleo |
| OPEP | Organisation des Pays Exportateurs de Pétrole (French: OPEC) |
| OPEP | Occupational Post-Exposure Prophylaxis |
| OPEP | Oil Pollution Emergency Plan (UK) |
| OPEP | Oscillating Positive Expiratory Pressure (respiratory therapy) |
| OPEP | Organização dos Países Exportadores de Petróleo (Portuguese) |
| OPEP | Ontario Pesticide Education Program (Canada) |
| OPEP | One-Pion Exchange Potential |
| OPEP | Organització de Països Exportadors de Petroli |
| OPEP | Orbit Plane Experiment Package |