| Abbreviation | Definition |
|---|---|
| OSA | Osaka, Japan |
| OSAP | Aleppo Neriab International, Syria |
| OSC | Oscoda-Wurtsmith Airport, Oscoda, Michigan USA (formerly Paul B. Wurtsmith Air Force Base) |
| OSD | Åre Östersund Airport, Östersund, Sweden |
| OSDI | Damascus International, Syria |
| OSDZ | Deirezzur, Syria |
| OSE | Omora, Papua New Guinea |
| OSG | Ossima, Papua New Guinea |
| OSH | Oshkosh, Wisconsin, USA |
| OSK | Oskarshamn, Sweden |
| OSKL | Kameshli, Syria |
| OSL | Oslo, Norway |
| OSLK | Latakia, Syria |
| OSP | Slupsk, Poland |
| OSPR | Palmyra, Syria |
| OSR | Ostrava, Czech Republic |
| OSS | Osh, Kyrgyzstan |
| OSW | Orsk, Russia |
| OSX | Kosciusko Airport / Attala County Airport, Kosciusko, Mississippi USA |
| OSY | Namsos, Norway |