| 1 | MQ | American Eagle Airlines, Inc. d/b/a American Eagle | ICAO: EGF, Callsign: Eagle Flight, Name changed to Executive Airlines, Inc. | USA | AVCODES |
| 2 | MQ | Simmons Airlines Inc. d/b/a American Eagle | ICAO: SYM, | USA | AVCODES |
| 3 | MQ | Societa Aerea Mediterranea (SAM) | Callsign: Air Sam, | I | AVCODES |
| 4 | MQ | Maldives Airways Ltd. | Callsign: Maldivesair, IATA designator changed to PN | MV | AVCODES |
| 5 | MQ | American Eagle Airlines, Inc. d/b/a American Eagle | ICAO: EGF, Callsign: Eagle Flight, Name changed to Envoy Air, Inc. ICAO designator changed to ENY. ICAO Callsign changed to Envoy. Designator MQ reinstated by IATA | USA | AVCODES |
| 6 | MQ | Envoy Air, Inc. | ICAO: ENY, Callsign: Envoy, IATA Prefix: 093, Name changed from American Eagle Airlines, Inc. d/b/a American Eagle, Inc. ICAO designator changed from EGF. ICAO Callsign changed from Eagle Flight. Designator MQ reinstated by IATA | USA | AVCODES |
| 7 | MQAB | MAIL CONTRACTORS OF AMERICA INC (BR | | | SCAC4 |
| 8 | MQAI | MARQUEZ TRUCKING | | | SCAC4 |
| 9 | MQAL | MCALISTER OIL COMPANY | | | SCAC4 |
| 10 | MQAM | MAIL CONTRACTORS OF AMERICA INC | | | SCAC4 |
| 11 | MQAP | MARQUARD | | | SCAC4 |
| 12 | MQAY | MAXIMUM TRANSPORTATION SYSTEMS INC | | | SCAC4 |
| 13 | MQCA | MCCARTY, CARL | | | SCAC4 |
| 14 | MQCB | MCBRIDE TRUCKING INC | | | SCAC4 |
| 15 | MQCC | MAQUINARIA Y LUBRICANTES DEL NOROES | | | SCAC4 |
| 16 | MQCD | DSR-MCCS | | | SCAC1 |
| 17 | MQCD | MEDITERRANEAN CANADA CONT. SVC. | | | SCAC4 |
| 18 | MQCH | MCH LLC | | | SCAC4 |
| 19 | MQCM | M C M ENTERPRISES | | | SCAC4 |
| 20 | MQCN | MICHOACANA H M, LA | | | SCAC4 |
| 21 | MQCO | METRO CONSOLIDATORS | | | SCAC4 |
| 22 | MQCR | MARINE CARGO | | | SCAC4 |
| 23 | MQCX | Monarch Cement Co. | added 4/1980; eliminated 4/1987; 1/1994 (not listed) | | NAKINA |
| 24 | MQCX | Marquette Co., a subsidiary of Gulf & Western Industries, Inc. | added 1/1979; 1/1980; eliminated 4/1980 | | NAKINA |
| 25 | MQCX | Marquette Co. | eliminated 1/1979 | | NAKINA |
| 26 | MQCX | Marquette Cement Manufacturing Co., a Division of Marquette Co. | added 10/1976 | | NAKINA |
| 27 | MQCX | Marquette Co. | added 7/1976; eliminated 10/1976 | | NAKINA |
| 28 | MQCX | Marquette Co. | added 7/76; eliminated 1/79 | | NRHS |
| 29 | MQCX | Marquette Co., a subsidiary of Gulf & Western Industries, Inc. | added 1/79; 1/80; eliminated 4/80 | | NRHS |
| 30 | MQCX | Monarch Cement Co. | added 4/80; eliminated 4/87; 1/94 | | NRHS |
| 31 | MQCX | MONARCH CEMENT COMPANY [MARQUETTE CO.] | | | PWRC |
| 32 | MQCX | Monarch Cement | | | RSRV |
| 33 | MQDC | MEDICI888 LLC | | | SCAC4 |
| 34 | MQDR | MCDONALD, BILLY J | | | SCAC4 |
| 35 | MQET | M T E EXPRESS | | | SCAC4 |
| 36 | MQFO | MURRAY & QUARLTERE FUEL OIL CORP | | | SCAC4 |
| 37 | MQGB | MAR LOGISTICS LLC | | | SCAC4 |
| 38 | MQGT | MISKIE, DAN TRUCKING | | | SCAC4 |
| 39 | MQGX | Morrison-Quirk Grain Corp. | added 7/1973; 1/1975-1/1980 | | NAKINA |
| 40 | MQGX | XTRA, Inc. | eliminated 1/1988 | | NAKINA |
| 41 | MQGX | Morrison-Quirk Grain Corp. | added 7/73; 1/75-1/80 | | NRHS |
| 42 | MQGX | XTRA, Inc. | eliminated 1/88 | | NRHS |
| 43 | MQGX | *MORRISON-QUIRK GRAIN CORP. | | | PWRC |
| 44 | MQGX | *RETIRED 11-24-92 ATP (1055) [XTRA INC.] | | | PWRC |
| 45 | MQGX | Morrison-Quirk Grain Corporation | | | RSRV |
| 46 | MQIS | MARQUIS, RON TRUCKING INC | | | SCAC4 |
| 47 | MQIT | M I T TRANSPORT LTD | | | SCAC4 |
| 48 | MQKN | MACKIN CONSTRUCTION CO | | | SCAC4 |
| 49 | MQLA | MITSUBISHI LOGISTICS AMERICA CORPOR | | | SCAC4 |
| 50 | MQLD | MONTROSE LOGISTICS LTD | | | SCAC4 |
| 51 | MQLI | METRO LOGISTICS INC | | | SCAC4 |
| 52 | MQLL | MILLER ENTERPRISES | | | SCAC4 |
| 53 | MQLU | MADDOX HOLDING B V | | | SCAC4 |
| 54 | MQMA | M M & A | | | SCAC4 |
| 55 | MQMC | M & M TRUCKING INC | | | SCAC4 |
| 56 | MQMI | MORRISON MARITIME INC EL SEGUNDO CA | | | SCAC4 |
| 57 | MQMT | MONUMENT TRANSPORTATION INC | | | SCAC4 |
| 58 | MQNA | MAC-NELS AGENCIES PTE LTD | | | SCAC4 |
| 59 | MQNC | MTM TRANSPORTATION INC | | | SCAC4 |
| 60 | MQNT | METRO T & C INC | | | SCAC4 |
| 61 | MQOI | MCCULLOUGH SNAPPY SERVICE OIL CO IN | | | SCAC4 |
| 62 | MQOJ | MORRIS, JACK OIL CO INC | | | SCAC4 |
| 63 | MQOT | MORTRANS INC | | | SCAC4 |
| 64 | MQPE | MARTIN PETROLEUM INC | | | SCAC4 |
| 65 | MQPF | MCCOY, WM | | | SCAC4 |
| 66 | MQPL | MIDWEST THREE (3) PL TRANSPORTATION | | | SCAC4 |
| 67 | MQPX | Millennium Inorganic Chemicals, Inc. | added 7/2000; 7/2000-7/2005 | | NAKINA |
| 68 | MQPX | Millennium Inorganic Chemicals, Inc. | added 7/2000; 7/2000 | | NRHS |
| 69 | MQPX | MILLENNIUM INORGANIC CHEMICALS, INC. | | | PWRC |
| 70 | MQPX | Millennium Inorganic Chemicals | | | RSRV |
| 71 | MQPX | MILLENNIUM INORGANIC CHEMICALS INC | | | SCAC4 |
| 72 | MQQC | MQ | | | SCAC4 |
| 73 | MQRA | MAQUITRADE SA DE CV | | | SCAC4 |
| 74 | MQRG | MORAN TRUCKING INC | | | SCAC4 |
| 75 | MQRN | MILES RANCH | | | SCAC4 |
| 76 | MQRP | M & R TRANSPORTATION SPECIALISTS LT | | | SCAC4 |
| 77 | MQRT | MARATHON TRANSPORT | | | SCAC4 |
| 78 | MQRX | Macquarie Rail Inc. | added 4/2008 | | NAKINA |
| 79 | MQRX | MACQUARIE RAIL, INC. | | | PWRC |
| 80 | MQRX | MACQUARIE RAIL INC | | | SCAC4 |
| 81 | MQSA | MASSEY FUEL INC | | | SCAC4 |
| 82 | MQSH | MOIRA SHIPPING COMPANY LIMITED | | | SCAC4 |
| 83 | MQSI | MOLD SERVICES INTERNATIONAL INC | | | SCAC4 |
| 84 | MQSP | MARQUARD | | | SCAC4 |
| 85 | MQSY | MARI-TECH SYSTEMS | | | SCAC4 |
| 86 | MQT | Air ITM S.A.S. | Callsign: Musketeer, | F | AVCODES |
| 87 | MQT | Air ITM | | | ICAO1 |
| 88 | MQT | Marquette Rail LLC | added 7/2006 | | NAKINA |
| 89 | MQT | MARQUETTE RAIL LLC | | | PWRC |
| 90 | MQT | Marquette Rail | | | RSRV |
| 91 | MQT | MARQUETTE RAIL LLC | | | SCAC4 |
| 92 | MQTB | MARQUISE TRANSPORTATION | | | SCAC4 |
| 93 | MQTD | MCMULLEN TRANSPORTATION & DELIVERY | | | SCAC4 |
| 94 | MQTE | MAC TEC S A DE C V | | | SCAC4 |
| 95 | MQTG | M & T TRUCKING LLC | | | SCAC4 |
| 96 | MQTK | MARQUIS, YVES TRUCKING | | | SCAC4 |
| 97 | MQTL | MARLOW TRUCKING COMPANY INC | | | SCAC4 |
| 98 | MQTN | M & T TRANSPORT | | | SCAC4 |
| 99 | MQTO | MARINE TRANS LOGISTICS | | | SCAC4 |
| 100 | MQTP | MATIC TRANSPORTATION INC | | | SCAC4 |
