| Airline Name | ICAO | IATA | Callsign | Country |
| Macair Airlines | MCK | CC | Australia | |
| Macedonian Airlines | MCS | Greece | ||
| Maersk Air | DAN | DM | Denmark | |
| Maersk Air UK | MSK | VB | United Kingdom | |
| Magenta Air | I2 | Peru | ||
| Magenta Aviation | United Kingdom | |||
| Magic Bird Airlines | Netherlands | |||
| Magic Blue Airlines | MJB | MAGIC BLUE | Netherlands | |
| Magic Carpet Aviation | United States | |||
| Magnicharters | GMT | UJ | GRUPOMONTERR EY | Mexico |
| Mahalo Air | MLH | 8M | United States | |
| Mahan Airlines | IRM | W5 | Iran, Islamic Republic Of | |
| Mahfooz Aviation | MZS | M2 | Saudi Arabia | |
| Makung Airlines | Taiwan | |||
| Malaysia Airlines | MAS | MH | MALAYSIAN | Malaysia |
| Malaysian-Singapore Airlines | ML | Multinational | ||
| Malev Express | MEH | Hungary | ||
| Malev Hungarian Airlines | MAH | MA | MALEV | Hungary |
| Malmo Aviation | SCW | TF | Sweden | |
| Mandala Airlines | MDL | RI | MANDALA | Indonesia |
| Mandarin Airlines | MDA | AE | MANDARIN | Taiwan |
| Mango | JE | South Africa | ||
| Manx Airlines | MNX | JE | United Kingdom | |
| MAP - Executive Flightservice | MPJ | Austria | ||
| Markair | MRK | United States | ||
| Markoss Aviation | MKO | United Kingdom | ||
| Maroomba Airlines | KN | Australia | ||
| Marsland Aviation | MSL | Sudan | ||
| Martinair Holland | MPH | MP | MARTINAIR | Netherlands |
| MAS Air Cargo | Mexico | |||
| Master Airways | Montenegro | |||
| Master Top Linhas Aereas | MTA | Brazil | ||
| MASwings | MAS | MH | Malaysia | |
| MAT Macedonian Airlines | MAK | IN | MAKAVIO | Macedonia, The Former Yugoslav Republic Of |
| Mauritania Airways | YD | Mauritania | ||
| Max Air | Nigeria | |||
| MAXavia | MAI | MAXAVIA | Kyrgyzstan | |
| Maximus Air Cargo | MXU | CARGO MAX | United Arab Emirates | |
| MaxJet | MXJ | MY | MAX-JET | United States |
| Mayan World Airlines | MYN | EY | Guatemala | |
| McDonnell Douglas | DAC | United States | ||
| McKee Food Transportation LLC | United States | |||
| MD Airlines | MDI | W3 | Iceland | |
| MDLR Airlines | India | |||
| MEA - Middle East Airlines | MEA | ME | CEDAR JET | Lebanon |
| Meadow Lane Air Partners LLC | United States | |||
| Med Airlines | MDS | M8 | Italy | |
| Med Trust | United States | |||
| Med-View Airlines | Nigeria | |||
| Medallion Air | MDP | Romania | ||
| Medavia -Mediterranean Aviation | MDM | Malta | ||
| Mediterranean Airlines | Egypt | |||
| Megantara Air | MKE | 9M | MEGANTARA | Indonesia |
| Mekong Airlines | MKN | M8 | Cambodia | |
| Menajet | MNJ | IM | Lebanon | |
| Meridiana | ISS | IG | MERAIR | Italy |
| Merpati | MNA | MZ | MERPATI | Indonesia |
| Mesa Airlines | ASH | YV | United States | |
| Mesaba Airlines | MES | XJ | United States | |
| Mesopotamia Air | Iraq | |||
| Metro Batavia | BTV | 7P | Indonesia | |
| Metro International | United States | |||
| Metroflight | MTR | United States | ||
| MetroJet | United States | |||
| Mexicana | MXA | MX | Mexico | |
| Mexicana de Carga | Mexico | |||
| Mexicana Link | MXI | I6 | LINK | Mexico |
| MGM Grand Air | MGM | MG | United States | |
| MGM Mirage | United States | |||
| Miami Air International | BSK | GL | United States | |
| MIAT - Mongolian Airlines | MGL | OM | Mongolia | |
| Mid Airlines | NYL | Sudan | ||
| Mid East Jet | Saudi Arabia | |||
| Mid-Pacific Airlines | MPA | United States | ||
| Midair | MLR | Liberia | ||
| MidAtlantic Airways | PDC | BK | United States | |
| Midex Airlines | MIX | MG | MIDEX CARGO | United Arab Emirates |
| Midroc Aviation | Ethiopia | |||
| Midway Airlines | MID | ML | United States | |
| Midway Express | FLA | United States | ||
| Midwest Airlines | MEP | YX | United States | |
| Midwest Airlines | MWA | MY | Egypt | |
| Midwest Express Airlines | MEP | YX | United States | |
| Mihin Lanka | Sri Lanka | |||
| Milne Bay Air (MBA Airline) | Papua New Guinea | |||
| Minerva Airlines | MTC | N4 | Italy | |
| Minerve | MIN | IW | France | |
| Minerve Canada | Canada | |||
| Miniliner | MNL | Italy | ||
| Mint Airways | MIC | MINT AIRWAYS | Spain | |
| Mistral Air | MSA | MISTRAL | Italy | |
| MK Airlines | MKA | 7G | KRUGER AIR | United Kingdom |
| MNG Airlines | MNB | MB | Turkey | |
| Mobil Oil | MBO | Canada | ||
| Mobilien Verwaltung | Germany | |||
| Modiluft | MOD | HT | India | |
| Moldavian Airlines | MDV | 2M | Moldova, Republic Of | |
| Monarch Airlines | MON | OM | MONARCH | United Kingdom |
| Mondair | MMA | Morocco | ||
| Montenegro Airlines | MGX | YM | MONTAIR | Montenegro |
| Morningstar Air Express | MAL | MORNINGSTAR | Canada | |
| Morris Air Service | MSS | United States | ||
| Moskovia Airlines | GAI | 3R | Russian Federation | |
| Motor-Sich | MSI | M9 | Ukraine | |
| Mountain Air Express | PKP | M7 | United States | |
| MTM Aviation | MTM | Germany | ||
| MUK Air | MUK | ZR | MUKAIR | Denmark |
| Multiflight Ltd | United Kingdom | |||
| Muse Air | MCA | MC | United States | |
| MyAir | MYW | 8I | FRANKY | Italy |
| Myanmar Airways | UBA | 8M | Myanmar | |
| Myrtle Beach Jet Expedition | United States | |||
| MyTravel | MYT | VZ | KESTREL | United Kingdom |
| MyTravel Airways | VKG | DK | VIKING | Denmark |
| MyTravelLite | MYL | VZ | United Kingdom |