| 1 | OAS | Oman Aviation Services Co. (SAOG) | IATA: WY, Callsign: Oryx, IATA Prefix: 910, Name changed to Oman Air (SAOG). ICAO callsign changed from Whiskey Yankee | OM | AVCODES |
| 2 | OAS | Oman Air (SAOG) | IATA: WY, Callsign: Oryx, IATA Prefix: 910, Name changed from Oman Aviation Services Co. (SAOG) | OM | AVCODES |
| 3 | OAS | Oasis Flight Ltd | | GB | AVCODES |
| 4 | OAS | Oman Aviation Services Co. (SAOG) | IATA: WY, Callsign: Whiskey Yankee, IATA Prefix: 910, Name changed to Oman Air (SAOG). ICAO callsign changed to Oryx | OM | AVCODES |
| 5 | OASB | ORIENT ALLIANCE SHIPPING COMPANY LI | | | SCAC4 |
| 6 | OASC | OASIS CARGO | | | SCAC3 |
| 7 | OASC | OCEAN ANGEL SHIPPING CO | | | SCAC4 |
| 8 | OASD | OASIS DENTAL GROUP INC | | | SCAC4 |
| 9 | OASE | OASIS ENTERPRISE INC | | | SCAC3 |
| 10 | OASI | OASIS COMPANY INC | | | SCAC3 |
| 11 | OASI | OASIS ENE | | | SCAC4 |
| 12 | OASK | OCEGUERA AND SONS TRUCKING | | | SCAC4 |
| 13 | OASL | OASIS ALIGNMENT SERVICES LTD | | | SCAC4 |
| 14 | OASS | OASIS LINES INC | | | SCAC3 |
| 15 | OASU | OCEAN AXIS SHIPPING SERVICES LLC | | UAE | BIC |
