| 1 | MG | Grand Holdings, Inc. d/b/a Champion Air | ICAO: CCP, Callsign: Champion Air, | USA | AVCODES |
| 2 | MG | Djibouti Airlines | ICAO: DJB, IATA designator changed to L2. IATA designator changed from DY / DJU | DJI | AVCODES |
| 3 | MG | Mediterranean Air Service | IATA designator changed to DR | TN | AVCODES |
| 4 | MG | MGM Grand Air, Inc. | ICAO: MGM, Callsign: Grand Air, | USA | AVCODES |
| 5 | MG | Malta Airlines | | M | AVCODES |
| 6 | MG | Midex Airlines | ICAO: MIX, Callsign: Midexcargo, IATA Prefix: 791, | UAE | AVCODES |
| 7 | MG | Miami Air Lease, Inc. | ICAO: MGD, Callsign: Miami Air, IATA Prefix: 424, Founded in 1971. | USA | AVCODES |
| 8 | MG | Moaf Airways | ICAO: MOF, Callsign: Mike Golf, | IL | AVCODES |
| 9 | MG | Eznis Airways LLC | ICAO: EZA, IATA Prefix: 116, Planned to start operations May 2018. | MGL | AVCODES |
| 10 | MG | Mobile & Gulf R.R. Co. | 1/1975-1/1980; eliminated 10/1985 | | NAKINA |
| 11 | MG | Mobile & Gulf R.R. Co. | 1/75-1/80 | | NRHS |
| 12 | MG | MOBILE & GULF RAILROAD CO. | | | PWRC |
| 13 | MG | Mobile and Gulf Railroad | | | RSRV |
| 14 | MG | Ferrovia Monte Generoso | | CH | TRAFFIC |
| 15 | MG | Ferrovia Monte Generoso SA | | CH | VKM |
| 16 | MGA | M G Aviacion, S.L. | Callsign: Mag Aviacion, | E | AVCODES |
| 17 | MGA | MG Aviacion | | | ICAO1 |
| 18 | MGA | Norfolk Southern Ry. Co. (Norfolk Southern) | 7/2000-7/2005 | | NAKINA |
| 19 | MGA | Consolidated Rail Corp. | added 7/1993; 1/1994; eliminated 7/1999 | | NAKINA |
| 20 | MGA | Monongahela Ry. Co. | 8/1920-10/1966 & 1/1975-1/1980; eliminated 7/1993 | | NAKINA |
| 21 | MGA | Monongahela Ry. Co. | 4/38-10/66 & 1/75-1/80; eliminated 7/93 | | NRHS |
| 22 | MGA | Consolidated Rail Corp. | added 7/93; 1/94; eliminated 7/99 | | NRHS |
| 23 | MGA | Norfolk Southern Ry. Co. (Norfolk Southern) | Jul-00 | | NRHS |
| 24 | MGA | NORFOLK SOUTHERN RWY [CONSOLIDATED RAIL CORP.; MONONGAHELA RY] | | | PWRC |
| 25 | MGA | Monongahela Railway (Norfolk Southern Railway) | | | RSRV |
| 26 | MGA | Monongahela Ry. Co. | | USA | TRAFFIC |
| 27 | MGAB | MGA LOGISTICS GROUP INC | | | SCAC4 |
| 28 | MGAC | Monongahela Connecting R.R. Co. | 7/1965-10/1966 | | NAKINA |
| 29 | MGAC | Monongahela Connecting R.R. Co. | 7/65-10/66 | | NRHS |
| 30 | MGAC | MONONGAHELA CONNECTING RAILROAD CO. | | | PWRC |
| 31 | MGAE | MEGA EXPRESS INC | | | SCAC4 |
| 32 | MGAH | MAPLE GROVE TOWING INC | | | SCAC4 |
| 33 | MGAJ | MEGA CARRIER CORPORATION | | | SCAC4 |
| 34 | MGAM | MORALES GARCIA, MARCOS | | | SCAC4 |
| 35 | MGAN | MORGAN OIL CORPORATION | | | SCAC4 |
| 36 | MGAP | MOUNTAIN MILK HAULING INC | | | SCAC4 |
| 37 | MGAQ | MARLOW, GERALD A | | | SCAC4 |
| 38 | MGAR | MCCALLUM, GARY | | | SCAC4 |
| 39 | MGAS | MORGAN SOUTHERN, INC | | | SCAC1 |
| 40 | MGAS | MORGAN SOUTHERN INC | | | SCAC4 |
| 41 | MGAT | MOGA TRANSPORT LTD | | | SCAC4 |
| 42 | MGAU | BONATESTA SRL | | | SCAC4 |
| 43 | MGAX | Moon Gasoline Co. | 7/1923-7/1932 | | NAKINA |
| 44 | MGAX | MOON GASOLINE CO. | | | PWRC |
| 45 | MGB | Coulson Flying Services Limited t/a Cranfield Flight Training | Callsign: Mockingbird, | GB | AVCODES |
| 46 | MGB | Coulson Flying Service | | | ICAO1 |
| 47 | MGB | Matterhorn-Gotthard-Bahn | MGB was created in 2003 through an amalgamation of Furka Oberalp Bahn (FO) and BVZ Zermatt-Bahn (BVZ). | CH | TRAFFIC |
| 48 | MGB | Matterhorn Gotthard Bahn Verkehrs AG | | CH | VKM |
| 49 | MGBC | M & G TRUCK BROKERAGE INC | | | SCAC4 |
| 50 | MGBC | M&G Bus Company | | USA | TRAFFIC |
| 51 | MGBH | MCMURDO, GLENN A | | | SCAC4 |
| 52 | MGBJ | MILLER, BOB RIGGING INC | | | SCAC4 |
| 53 | MGBM | MG TRANSPORT | | | SCAC4 |
| 54 | MGBN | MG & BD TRUCKING | | | SCAC4 |
| 55 | MGBP | MR G TRUCKING INC | | | SCAC4 |
| 56 | MGBU | A P MOLLER | | | SCAC4 |
| 57 | MGBV | MARITIME GLOBAL LOGISTICS | | | SCAC4 |
| 58 | MGC | Magec Aviation Limited | Callsign: Magec, | GB | AVCODES |
| 59 | MGC | Air Cargo Mongolia | Callsign: Mongolia Cargo, | MGL | AVCODES |
| 60 | MGCD | MILGRAM & COMPANY LTD | | | SCAC4 |
| 61 | MGCJ | MULTI GROUP LOGISTICS INC | | | SCAC4 |
| 62 | MGCL | M G CHEMICALS LTD | | | SCAC4 |
| 63 | MGCM | M G CABINETS & MILLWORK LTD | | | SCAC4 |
| 64 | MGCO | MACLEOD GENERAL CONST LTD | | | SCAC4 |
| 65 | MGCP | MORRIS, GENE COMPANY INC | | | SCAC4 |
| 66 | MGCT | MAGIC TRANSPORT | | | SCAC4 |
| 67 | MGCU | MAC FIELD GROUP OF COMPANIES, THE | | | SCAC4 |
| 68 | MGCW | MTI LOGISTICS LLC | | | SCAC4 |
| 69 | MGCX | Morrison Grain Co. | added 1/1967; eliminated 4/1967 | | NAKINA |
| 70 | MGCX | Morrison Grain Co. | added 1/67; eliminated 4/67 | | NRHS |
| 71 | MGCX | MORRISON GRAIN CO. | | | PWRC |
| 72 | MGCY | MAGIC TRANSPORTATION COMPANY INC | | | SCAC4 |
| 73 | MGD | Miami Air Lease, Inc. | IATA: MG, Callsign: Miami Air, IATA Prefix: 424, Founded in 1971. | USA | AVCODES |
| 74 | MGDA | MAGNOLIA DISTRIBUTION OF ATLANTA IN | | | SCAC4 |
| 75 | MGDB | MORGAN DISTRIBUTING INC | | | SCAC4 |
| 76 | MGDE | MAGNUM DEDICATED INC | | | SCAC4 |
| 77 | MGDG | MARTINEZ GRAJALES, DIEGO ACOMIZTLI | | | SCAC4 |
| 78 | MGDH | MGD SHIPPING S P A | | | SCAC4 |
| 79 | MGDJ | MCGEE, DALLAS JAMES | | | SCAC4 |
| 80 | MGDK | MATAR GENERAL TRADE INC | | | SCAC4 |
| 81 | MGDO | MEADOW GOLD DAIRIES | | | SCAC4 |
| 82 | MGDP | MAG-DOUGLAS TRANSPORT CORP | | | SCAC4 |
| 83 | MGDR | MARTIN, GERALD TRANSPORT | | | SCAC4 |
| 84 | MGDS | MESSENGER FREIGHT SYSTEMS | | | SCAC4 |
| 85 | MGDT | MAGDA SHIPPING LTD | | | SCAC4 |
| 86 | MGDY | MILLS, STEVEN A TRUCKING | | | SCAC4 |
| 87 | MGDY | Przedsiębiorstwo Komunikacji Miejskiej w Gdyni | | PL | TRAFFIC |
| 88 | MGE | Aero Micronesia Inc d/b/a Asia Pacific Airlines | IATA: P9, Callsign: Magellan, IATA Prefix: 046, | GUM | AVCODES |
| 89 | MGE | Asia Pacific Airlines | | | ICAO1 |
| 90 | MGE | Asia Pacific Airlines | Based on Guam | USA | TRAFFIC |
| 91 | MGEF | MORGAN TRANSFER INC | | | SCAC4 |
| 92 | MGEG | MAGIC MESSENGER INC | | | SCAC4 |
| 93 | MGEJ | MISTER G ENTERPRISE INC | | | SCAC4 |
| 94 | MGEK | MARGIE TRUCKING CO INC | | | SCAC4 |
| 95 | MGEL | MANGUMS INC | | | SCAC4 |
| 96 | MGEN | MAGENTA | | | SCAC4 |
| 97 | MGES | MARTIME-GESE | | | SCAC4 |
| 98 | MGET | MCGEE TRUCKING | | | SCAC4 |
| 99 | MGEU | MONTER GLOBAL LOGISTICS (S) PTE LTD | | SGP | BIC |
| 100 | MGEW | MCGREW TRUCKING | | | SCAC4 |
