| Abbreviation | Definition |
|---|---|
| OAP | Oceanic Automation Program |
| OAS | Office of Aircraft Services |
| OAS | Offshore Access System |
| OASIS | Observation Aided Safety Improvement System |
| OASIS | Operational and Supportability Implementation System |
| OB | Over Boost |
| OBD | Operation Buckle Down |
| OBOL | Ocean Bill Of Lading |
| OBOR | One Belt One Road |
| OBS | Outward Bound Singapore |
| OBV | On Balance Volume |
| OBV | Orbital Boost Vehicle |
| OC | Obstruction Chart |
| OC | Outrigger Canoe |
| OCAS | Obstacle Collision Avoidance System |
| OCB | On Company Business |
| OCBB | Old Car Buy Back |
| OCC | Operations Control Center |
| OCFB | On Car Flow Bench |
| OCL | Orient Cargo Line |