| 1 | MO | Calm Air International Ltd. | ICAO: CAV, Callsign: Calm Air, IATA Prefix: 622, Canadian Partner | CDN | AVCODES |
| 2 | MO | Abu Dhabi Amiri Flight | ICAO: AUH, Callsign: Sultan, Designator OM* recaled by IATA | UAE | AVCODES |
| 3 | MO | Mohawk Airlines, Inc. | Callsign: Mohawk, | USA | AVCODES |
| 4 | MO | Airmore Aviation | ICAO: NAA, Callsign: National, | GB | AVCODES |
| 5 | MO | Cosmos Aviation Services (Private) Ltd. | ICAO: CMK, Callsign: Comos Lanka, | CL | AVCODES |
| 6 | MO | MOBIL OIL | | | PWRC |
| 7 | MO | Martigny - Orsieres | | CH | TRAFFIC |
| 8 | MOA | Air Moravia Czech Charter Airline Ltd. | Callsign: Moras, | CZ | AVCODES |
| 9 | MOA | Moana Airlines | Callsign: Moana, | NZ | AVCODES |
| 10 | MOA | Moscow Airlines, JSC | IATA: 7B, Callsign: Moscow Airlines, Ceased operations on 17 January 2011. Name changed from Atlant-Soyuz Airlines w.e.f. 17 September 2010. | RUS | AVCODES |
| 11 | MOAA | MOTOR CARRIER SERVICE INC | | | SCAC4 |
| 12 | MOAB | MORGAN TRANSPORT | | | SCAC4 |
| 13 | MOAC | MACH ONE (1) AIR SERVICES INC | | | SCAC4 |
| 14 | MOAD | MOORE, A ENTERPRISES INC | | | SCAC4 |
| 15 | MOAE | MORRIS, A. E | | | SCAC1 |
| 16 | MOAG | MORGAN, ANGELA INC | | | SCAC4 |
| 17 | MOAH | MONTERO SHIPPING CORP | | | SCAC4 |
| 18 | MOAJ | MODLIN, WILLIAM INC | | | SCAC4 |
| 19 | MOAK | MORRIS SEALCOAT & TRUCKING INC | | | SCAC4 |
| 20 | MOAL | MONSTER AESTHETICS | | | SCAC4 |
| 21 | MOAN | MOVIN ON TRANSPORTATION INC | | | SCAC4 |
| 22 | MOAO | MONTAG OIL INC | | | SCAC4 |
| 23 | MOAP | MOAPA VALLEY FREIGHT AND PASSENGER SERVICE | | | SCAC1 |
| 24 | MOAT | MOBILE SERVICE INC | | | SCAC4 |
| 25 | MOAU | MITSUI O.S.K. LINES LTD | | J | BIC |
| 26 | MOAU | MITSUI O S K LINES LTD | | | SCAC4 |
| 27 | MOAV | MACH ONE (1) AIR SERVICE INC (AIR F | | | SCAC4 |
| 28 | MOAW | MORTIMER & WALLACE INC | | | SCAC4 |
| 29 | MOB | MITSUI O.S.K. LINES, LTD. | | | PWRC |
| 30 | MOB | Montreux-Oberland-Bernois | | CH | TRAFFIC |
| 31 | MOB | Compagnie du Chemins de fer Montreux-Oberland bernois | | CH | VKM |
| 32 | MOBD | MOBREN LOGISTICS LLC | | | SCAC4 |
| 33 | MOBE | MOORE BROTHERS TRANSPORT LTD | | | SCAC4 |
| 34 | MOBI | Mobilis | | PL | TRAFFIC |
| 35 | MOBJ | MOBRO MARINE INC | | | SCAC4 |
| 36 | MOBR | MONTY, BRIAN | | | SCAC4 |
| 37 | MOBS | M-INT AUTO MOTIVE | | | SCAC4 |
| 38 | MOBT | MAMMOET TRANSPORTATION INC | | | SCAC4 |
| 39 | MOBU | MOVE INTERMODAL NV | | B | BIC |
| 40 | MOBU | MUELLE ORIENTAL S A | | | SCAC4 |
| 41 | MOBUS | MöBus | City: Mönchengladbach | D | TRAFFIC |
| 42 | MOBV | MID ORIENT BAKERY | | | SCAC4 |
| 43 | MOBX | Exxon Mobil Corp. | added 7/2000; 7/2000-7/2005 | | NAKINA |
| 44 | MOBX | Mobil Oil Corp. | added 10/1966; 10/1966-1/1994; eliminated 7/2000 | | NAKINA |
| 45 | MOBX | Mobil Oil Co., a Division of Socony Mobil Oil Co., Inc. | added 4/1960; eliminated 10/1966 | | NAKINA |
| 46 | MOBX | Socony Mobil Oil Co., Inc. | 4/61-7/65 | | NRHS |
| 47 | MOBX | Mobil Oil Co., a Division of Socony Mobil Oil Co., Inc. | eliminated 10/66 | | NRHS |
| 48 | MOBX | Mobil Oil Corp. | added 10/66; 10/66-1/94; eliminated 7/2000 | | NRHS |
| 49 | MOBX | Exxon Mobil Corp. | added 7/2000; 7/2000 | | NRHS |
| 50 | MOBX | EXXON-MOBIL CORP. [MOBIL OIL CORPORATION] | | | PWRC |
| 51 | MOBX | Mobil Oil Corporation (Exxon-Mobil Corporation) | | | RSRV |
| 52 | MOBX | EXXON MOBIL CORPORATION | | | SCAC4 |
| 53 | MOBX | Mobil Oil Corp. | | USA | TRAFFIC |
| 54 | MOBY | MOBY MARINE CORP | | | SCAC4 |
| 55 | MOC | Air Monacrch Cargo, S.A. de C.V. | Callsign: Monarch Cargo, | MEX | AVCODES |
| 56 | MOC | Aero Marat, S.A. de C.V. | Callsign: Aeromarat, | MEX | AVCODES |
| 57 | MOC | Air Monarch Cargo | | | ICAO1 |
| 58 | MOC | Missouri Central R.R. Co. | 7/2000-7/2005 | | NAKINA |
| 59 | MOC | Missouri Central R.R. Co. | Jul-00 | | NRHS |
| 60 | MOC | MISSOURI CENTRAL RAILROAD | | | PWRC |
| 61 | MOC | Missouri Central Railroad | | | RSRV |
| 62 | MOC | MISSOURI CENTRAL RAILROAD COMPANY | | | SCAC4 |
| 63 | MOCA | MARTIN OIL COMPANY INC | | | SCAC4 |
| 64 | MOCB | MUTCH OIL CO OF GRAND FORKS INC | | | SCAC4 |
| 65 | MOCD | MATSON OIL COMPANY INC | | | SCAC4 |
| 66 | MOCG | MORFINI SPA | | | SCAC4 |
| 67 | MOCI | MEYERS OIL COMPANY INC | | | SCAC4 |
| 68 | MOCK | MONSON TRUCK LINE INC | | | SCAC4 |
| 69 | MOCL | Montgomery City Lines | City: Montgomery, AL | USA | TRAFFIC |
| 70 | MOCN | MURPHY OIL COMPANY INCORPORATED | | | SCAC4 |
| 71 | MOCO | MCINTOSH OIL CO INC | | | SCAC4 |
| 72 | MOCP | MORAN, CHRISTIAN TRANSPORT | | | SCAC4 |
| 73 | MOCR | MCGILLVREY OIL CO INC | | | SCAC4 |
| 74 | MOCU | MACS MARITIME CARRIER SHIPPING GMBH & CO | | D | BIC |
| 75 | MOCU | MACS MARITIME CARRIER SHIPPING GMBH | | | SCAC4 |
| 76 | MOCX | The Mosaic Co. | added 1/2010 | | NAKINA |
| 77 | MOCX | Missouri Portland Cement Co. | 1/1941; 4/1947-1/1980; eliminated 10/1984 | | NAKINA |
| 78 | MOCX | Missouri Portland Cement Co. | 1/52-1/80; eliminated 10/84 | | NRHS |
| 79 | MOCX | MISSOURI PORTLAND CEMENT COMPANY | | | PWRC |
| 80 | MOCX | Missouri Portland Cement | | | RSRV |
| 81 | MOCX | MOSAIC COMPANY, THE | | | SCAC4 |
| 82 | MOCZ | MURPHY OIL COMPANY | | | PWRC |
| 83 | MOD | Modiluft Limited | IATA: HT, Callsign: Modiluft, IATA Prefix: 548, Ceased operations in 1996. AOC transferred to Royal Airways t/a SpiceJet | IND | AVCODES |
| 84 | MOD | Royal Airlines Limited | IATA: 0S, Callsign: Modiluft, Name changed to Royal Airlines Limited d/b/a Spice Jet | IND | AVCODES |
| 85 | MOD | Royal Airlines Limited d/b/a Spice Jet | IATA: 0S, Callsign: Modiluft, Name changed from Royal Airlines Limited. IATA designator changed to SG. | IND | AVCODES |
| 86 | MOD | Royal Airlines Limited d/b/a Spice Jet | IATA: SG, Callsign: Modiluft, ICAO designator changed to SEJ. ICAO callsign changed to Spicejet. Name changed from Royal Airlines Limited. IATA designator changed from 0S. | IND | AVCODES |
| 87 | MOD | Aeroclube de Coimbra | Callsign: Mondego, | P | AVCODES |
| 88 | MOD | Missouri Pacific System | eliminated 10/1981; eliminated 5/1983 | | NAKINA |
| 89 | MOD | Missouri Pacific Railroad Co. | added 1/1977; 1/1980 | | NAKINA |
| 90 | MOD | Texas and Pacific Railway Co. | 1/1975; eliminated 1/1977 | | NAKINA |
| 91 | MOD | Texas and Pacific Railway Co. | 1/75; eliminated 1/77 | | NRHS |
| 92 | MOD | Missouri Pacific Railroad Co. | added 1/77; 1/80 | | NRHS |
| 93 | MOD | Missouri Pacific System | eliminated 10/81; eliminated 5/83 | | NRHS |
| 94 | MOD | UNION PACIFIC [MISSOURI PACIFIC SYSTEM; TEXAS & PACIFIC RWY. CO.] | | | PWRC |
| 95 | MOD | Missouri Pacific Railroad | | | RSRV |
| 96 | MODE | MODESTI BROS | | | SCAC1 |
| 97 | MODE | MODESTI BROS INC | | | SCAC4 |
| 98 | MODF | MOLINA TRANSPORTATION | | | SCAC4 |
| 99 | MODH | MONTGOMERY OIL INC | | | SCAC4 |
| 100 | MODJ | MODULEULTRA | | | SCAC4 |
