| 1 | ORE | Greendale Aviation Company Ltd. | Callsign: Rekoya, | WAN | AVCODES |
| 2 | ORE | Orange Aviation | | | ICAO1 |
| 3 | OREC | OMEGA RECICLYNG | | | SCAC4 |
| 4 | OREE | ORIENTAL EXPRESS | | | SCAC3 |
| 5 | OREG | OREGRO SEEDS INC | | | SCAC4 |
| 6 | OREK | OAK RIDGES ENTERPRISES INC | | | SCAC4 |
| 7 | OREN | ORENELAS ARMENTA, PABLO | | | SCAC4 |
| 8 | OREN | | City: Orenburg | RUS | TRAFFIC |
| 9 | OREQ | OREGON TRUCK LINE | | | SCAC3 |
| 10 | ORER | ORNELAS RIVERA, JOSE DE JESUS | | | SCAC4 |
| 11 | ORET | OREGON TRANSFER CO | | | SCAC3 |
| 12 | ORET | OREGON TRANSFER CO | | | SCAC4 |
| 13 | OREU | ORIENT EXPRESS LLC | | RUS | BIC |
| 14 | OREU | ORIENT EXPRESS LLC | | | SCAC4 |
| 15 | OREX | Oregon Dept. of Agriculture | 1/1994-7/2005 (not listed) | | NAKINA |
| 16 | OREX | REA Express, Inc. | added 10/1970; added 1/1971; eliminated 4/1974 | | NAKINA |
| 17 | OREX | REA Express, owned and operated by Railway Express Agency, Inc. | eliminated 1/1971 | | NAKINA |
| 18 | OREX | REA Express | added 10/1970 | | NAKINA |
| 19 | OREX | Omaha Refining Co. | 8/1920 | | NAKINA |
| 20 | OREX | REA Express | added 10/70; eliminated 4/74 | | NRHS |
| 21 | OREX | Oregon Dept. of Agriculture | 1/94-7/2000 | | NRHS |
| 22 | OREX | *OMAHA REFINING CO. | | | PWRC |
| 23 | OREX | *REA EXPRESS, INC. (RAILWAY EXPRESS AGENCY, INC.) | | | PWRC |
| 24 | OREX | +OREGON DEPARTMENT OF AGRICULTURE | | | PWRC |
| 25 | OREX | Oregon Department of Agriculture | | | RSRV |
| 26 | OREX | OREGON DEPARTMENT OF AGRICULTURE | | | SCAC4 |
| 27 | OREY | OSPREY SHIPPING LLC | | | SCAC4 |
