| 1 | OW | Executive Airlines, Inc. | ICAO: EXW, Callsign: Echoline, IATA Prefix: 092, Ceased operations on 01 April 2013. Name changed from American Eagle Airlines, Inc. d/b/a American Eagle | USA | AVCODES |
| 2 | OW | Cargosur | ICAO: OWS, Designator OW recalled by IATA. Now uses IB prefix. | E | AVCODES |
| 3 | OW | Metavia Airlines Pty. Ltd. | ICAO: MNK, Callsign: Viamet, Designator recalled by IATA | ZA | AVCODES |
| 4 | OW | Owenair (PTY) Ltd. | Callsign: Owenair, | ZA | AVCODES |
| 5 | OW | Executive Airlines, Inc. | ICAO: EXK, Designator OW reinstated by IATA | USA | AVCODES |
| 6 | OW | Executive Airlines, Inc. | ICAO: EXK, | USA | AVCODES |
| 7 | OW | Skyward Express Ltd. | ICAO: SEW, Callsign: Skyward Express, | EAK | AVCODES |
| 8 | OW | New York, Ontario & Western Ry. | 4/1938-7/1954 | | NAKINA |
| 9 | OW | New York, Ontario & Western Ry. Co. | 7/1923-7/1930 | | NAKINA |
| 10 | OW | New York, Ontario & Western Ry. | 4/38-1/52 | | NRHS |
| 11 | OW | NEW YORK, ONTARIO & WESTERN RY | | | PWRC |
| 12 | OW | New York, Ontario & Western | | USA | TRAFFIC |
| 13 | OWAB | OLSON & WRIGHT AB | | | SCAC3 |
| 14 | OWAB | OGAWA ENTERPRISES INC | | | SCAC4 |
| 15 | OWAC | OTTAWA CLASSIC STAIRS INC | | | SCAC4 |
| 16 | OWAP | OWENS AUTO PARTS INC | | | SCAC3 |
| 17 | OWAU | OCEAN WAYS INC | | | SCAC4 |
| 18 | OWB | Oberweißbacher Bergbahn | | D | TRAFFIC |
| 19 | OWBE | OWNBEY ENTERPRISES INC | | | SCAC4 |
| 20 | OWBL | OSWALT, LARRY TRUCKING INC | | | SCAC4 |
| 21 | OWBM | OWEN BROS MOVING & STORAGE | | | SCAC3 |
| 22 | OWBN | ONEWAYTRAILERS.COM | | | SCAC4 |
| 23 | OWBT | OWEN BROS TRUCKING & LIME CO | | | SCAC3 |
| 24 | OWCB | OLD WORLD COLLECTIBLES | | | SCAC4 |
| 25 | OWCI | OLSON WAREHOUSE COMPANY INC | | | SCAC3 |
| 26 | OWCL | OCEANWIDE CONTAINER LINES (DIV OF C | | | SCAC3 |
| 27 | OWCL | OCEANWIDE CONTAINER LINES (DIV OF C | | | SCAC4 |
| 28 | OWCP | OWL CORP, THE | | | SCAC4 |
| 29 | OWCR | OWENS, C R | | | SCAC3 |
| 30 | OWCZ | OMACK WOOD COMPANY | | | PWRC |
| 31 | OWDE | OAKWOOD ENTERPRISES INC | | | SCAC3 |
| 32 | OWDL | ONE WAY DELIVERY INC | | | SCAC3 |
| 33 | OWDN | OWENS, DON TRUCKING | | | SCAC3 |
| 34 | OWDR | OLD WORLD DOOR LLC | | | SCAC4 |
| 35 | OWE | Owenair (Pty) Ltd. | IATA: UD, Callsign: Owenair, Designator UD* recalled by IATA. | ZA | AVCODES |
| 36 | OWE | Owenair (Pty) Ltd. | Callsign: Owenair, Designator UD* recalled by IATA. | ZA | AVCODES |
| 37 | OWEA | OLD WEST EXPRESS INC | | | SCAC4 |
| 38 | OWEB | OWENS BROS TRANSFER CO | | | SCAC3 |
| 39 | OWEC | OWNERS EXPRESS INC | | | SCAC3 |
| 40 | OWED | OMADA WORLDWIDE EXPEDITE INC | | | SCAC4 |
| 41 | OWEG | OWEN TRUCKING INC | | | SCAC4 |
| 42 | OWEI | OWENS TRUCKMEN INC | | | SCAC3 |
| 43 | OWEI | OWENS TRUCKMEN INC | | | SCAC4 |
| 44 | OWEJ | OWENS, JERRY TRUCKING CO | | | SCAC3 |
| 45 | OWEK | OWENS TRUCKING | | | SCAC3 |
| 46 | OWEK | OWENS TRUCKING | | | SCAC4 |
| 47 | OWEN | OWENS CFS INC | | | SCAC4 |
| 48 | OWEN | Owen's Coaches | | GB | TRAFFIC |
| 49 | OWEQ | OWENS TRUCKING SERVICE INCORPORATED | | | SCAC3 |
| 50 | OWET | OWENS TRANSPORT SERVICE | | | SCAC4 |
| 51 | OWEU | Owens Energy | | | RSRV |
| 52 | OWEW | OWENS, EDWARD D | | | SCAC3 |
| 53 | OWEY | ONE WAY EXPRESS INC | | | SCAC4 |
| 54 | OWFL | OKANAGAN WOOD FIBRE LTD | | | SCAC4 |
| 55 | OWFT | OWENS FREIGHT LINES INC | | | SCAC3 |
| 56 | OWHI | OTT, W H INC | | | SCAC3 |
| 57 | OWHT | OWEN, HARRY TRUCKING INC | | | SCAC3 |
| 58 | OWHU | OY HACKLIN LTD | | | SCAC4 |
| 59 | OWI | Aerowin, S.A. de C.V. | Callsign: Aerowin, | MEX | AVCODES |
| 60 | OWI | Oneida & Western Railroad | | USA | TRAFFIC |
| 61 | OWIC | OLIVER, WILLIAM | | | SCAC4 |
| 62 | OWIF | ONE WORLD INDUSTRIES INC | | | SCAC4 |
| 63 | OWII | OWENS ILLINOIS INC | | | PWRC |
| 64 | OWII | OAKWOOD INVESTMENTS MONROVIA LIBERI | | | SCAC3 |
| 65 | OWIQ | OWINGS, DALE, DONALD OWINGS & RONAL | | | SCAC3 |
| 66 | OWIS | OWINGS TRANSPORT INC | | | SCAC3 |
| 67 | OWIX | Old World Transportation, Ltd. | added 4/2001; 7/2005 | | NAKINA |
| 68 | OWIX | Old World Industries Ltd. | added 1/2001; eliminated 4/2001 | | NAKINA |
| 69 | OWIX | Owens-Illinois Glass Co., Mill Division | added 4/1959; 4/1961; eliminated 1/1964 | | NAKINA |
| 70 | OWIX | Owens-Illinois Glass Co., Mill Division | Apr-61 | | NRHS |
| 71 | OWIX | Old World Industries Ltd. | added 1/2001; eliminated 4/2001 | | NRHS |
| 72 | OWIX | Old World Transportation, Ltd. | added 4/2001 | | NRHS |
| 73 | OWIX | *OWENS-ILLINOIS GLASS CO., MILL DIVISION | | | PWRC |
| 74 | OWIX | +OLD WORLD TRANSPORTATION, LTD. | | | PWRC |
| 75 | OWIX | Old World Transportation | | | RSRV |
| 76 | OWIX | OLD WORLD INDUSTRIES I LTD | | | SCAC4 |
| 77 | ÖWJ | Östra Värmlands Järnväg | 1873 - 1897 | S | svenska-lok.se |
| 78 | OWJN | OWEN, JOHN TRUCKING INC | | | SCAC3 |
| 79 | OWKC | OLD WORLD KITCHENS AND CUSTOM CABIN | | | SCAC4 |
| 80 | OWKG | OLSON, WM., TRUCKING, INC | | | SCAC3 |
| 81 | OWKN | OWEN-KENNEDY INC | | | SCAC3 |
| 82 | OWKN | OWEN-KENNEDY INC | | | SCAC4 |
| 83 | OWKW | OSKAR WEHR KG (GMBH & CO) | | | SCAC4 |
| 84 | OWL | Miami Valley Aviation, Inc. | Callsign: Night Owl, | USA | AVCODES |
| 85 | OWL | Miami Valley Aviation | | | ICAO1 |
| 86 | OWL | OHARE WISCONSIN LIMOUSINE SERVICE I | | | SCAC4 |
| 87 | OWLA | OWLS ATHLETIC CLUB INC | | | SCAC3 |
| 88 | OWLC | OLD WEST LIVESTOCK LLC | | | SCAC4 |
| 89 | OWLD | ONE-WAY LOGISTICS INCORPORATED | | | SCAC4 |
| 90 | OWLI | O W L TRANSPORT INC | | | SCAC3 |
| 91 | OWLI | O W L TRANSPORT INC | | | SCAC4 |
| 92 | OWLL | OWL LTD | | | SCAC3 |
| 93 | OWLL | OWL LTD | | | SCAC4 |
| 94 | OWLN | OCEAN WORLD LINES | | | SCAC4 |
| 95 | OWLO | ONE-WAY LOGISTICS INCORPORATED OF I | | | SCAC4 |
| 96 | OWLQ | OWL DELIVERY SERVICE | | | SCAC3 |
| 97 | OWLS | OWL TRANSFER & STORAGE COMPANY, INC | | | SCAC3 |
| 98 | OWLS | OWL TRANSFER & STORAGE COMPANY INC | | | SCAC4 |
| 99 | OWLU | ONE WAY LEASE INC. | | USA | BIC |
| 100 | OWLU | OCEAN WORLD LINES, INC. | | | PWRC |
