| 1 | OCM | O'Connor Airlines | IATA: UQ, Callsign: O'Connor, Name changed from O'Connor-Mt. Gambier's Airline | AUS | AVCODES |
| 2 | OCM | O'Connor-Mt. Gambier's Airline | IATA: UQ, Callsign: O'Connor, Name changed to O'Connor Airlines | AUS | AVCODES |
| 3 | OCMD | OCEAN CITY, MAYOR AND CITY COUNCIL | | | SCAC3 |
| 4 | OCME | OAK CLIFF METALS | | | SCAC4 |
| 5 | OCMF | ONE CALL MOTOR FREIGHT INC | | | SCAC3 |
| 6 | OCMG | ORANGE COAST MOVING SYSTEMS INC | | | SCAC3 |
| 7 | OCMP | OCEANIC COMP LTD | | | SCAC3 |
| 8 | OCMP | OCEANIC COMP LTD | | | SCAC4 |
| 9 | OCMR | OCEANMARIS MANAGEMENT INC | | | SCAC3 |
| 10 | OCMS | OXBOW CARBON & MINERALS LLC | | | SCAC4 |
| 11 | OCMU | OC Container | | | RSRV |
| 12 | OCMU | OC CONTAINER CORP | | | SCAC4 |
