| Company | Search On | Records | Category | Sub category |
| Macfarlane Thirsk (Engineers) Ltd | MacfarlaneThirsk | 1 | Manufacturing | Machining |
| Macks Structures (London) Ltd | MacksStructures | 3 | Structures | Hangars |
| Maclennan and Co. John | Maclennan | 13 | Fixtures and Fittings | AGS |
| Macready's Metals Co Ltd | MacreadysMetals | 2 | Manufacturing | Steel |
| Macrome Ltd | Macrome | 47 | Engineering Equipment | Machining |
| Madgwick Ltd | Madgwick | 1 | Logistics | Packaging |
| Magenta Time Company Ltd | Magenta | 13 | Factory | PA Broadcast Systems |
| Magnesium Castings & Products Ltd | MagnesiumCastings | 59 | Manufacturing | Castings |
| Magnesium Elektron Ltd | MagnesiumElektron | 36 | Materials | Elektron |
| Magnetic Devices Ltd | MagneticDevices | 2 | Components | Electrical |
| Magnesium Castings & Products Ltd | Maguminium | 2 | Materials | Magnesium Alloys |
| Malcolm Farquharson Ltd | MalcolmFarquharson | 2 | Aircraft Suppliers | |
| Mallinson & Eckersley Ltd | MallinsonEckersley | 6 | Factory | Logistics |
| Mallock Armstrong Ear Defender Co | MallockArmstrong | 29 | Clothing | Safety |
| M.A.N.Turbo GMBH |
M.A.N. | 1 | Engine Manufacturers | Non UK |
| Manganese Bronze And Brass Co Ltd | ManaganeseBronze | 22 | Components | Bearings |
| Manchester Oil Refinery (Sales) Ltd | ManchesterOil | 3 | Chemicals | NDT |
| Mann Egerton & Co Ltd | MannEgerton | 12 | Aircraft Manufacturers | |
| Taylor, Bolton. George | Manufacturing | 113 | Manufacturing | Castings |
| Marconis Wireless Telegraph Co Ltd | Marconi | 498 | Avionics | Wireless |
| Marconi-Elliott Avionic Systems Ltd | MarconiElliott | 11 | Avionics | Radio |
| Maricon Ltd | Maricon | 8 | Components | Refuelling |
| Marshall Osborne & Co Ltd | MarshallOsborne | 1 | Materials | Bearium Bronze |
| Marshalls Flying School Ltd | Marshalls | 18 | Training | Flying School |
| Marsh Brothers & Co Ltd | MarshBrothers | 11 | Fasteners | Wire |
| Marston Ltd. John | Marston | 12 | Components | Radiators |
| Marston Excelsior Ltd | MarstonExcelsior | 95 | Components | Radiators |
| Martin Company. The Glen L. |
Martin | 26 | Aircraft Manufacturers | Non UK |
| Martin-Baker Aircraft Co | MartinBaker | 358 | Survival Equipment | Ejector Seats |
| Martindale Electric Co Ltd | Martindale | 6 | Ground Equipment | Cleaning Tools |
| Martinsyde Ltd | Martinsyde | 33 | Aircraft Manufacturers | |
| Martin Thomas Ltd | MartinThomas | 5 | Ground Equipment | Staging |
| Marwin Machine Tools Ltd | MarwinMachineTools | 2 | Engineering Equipment | Machine Tools |
| Masson Seeley & Co Ltd | MassonSeeley | 2 | Manufacturing | Precision Engineering |
| Mastermodels Ltd | Mastermodels | 5 | Models | Display |
| Matchbox. Lesney Products | Matchbox | 7 | Models | Display |
| Materials. (Misc) | Materials | 24 | Materials | Bronze |
| Matra | Matra | 22 | Weapons | Missiles |
| Matthews & Yates Ltd | MatthewsYates | 2 | Components | Electrical |
| Maule | Maule | 4 | Aircraft Manufacturers | Non UK |
| Mavitta Drafting Machines Ltd | Mavitta | 28 | Engineering Equipment | Drafting |
| May & Baker Ltd | MayBaker | 5 | Materials | Transparencies |
| Maybrey. H.J. | Maybrey | 1 | Manufacturing | Castings |
| Mayrow Industrial Systems Ltd. The | Mayrow | 1 | Manufacturing | Components |
| Mayro-Wing Aviation Co | MayroWing | 1 | Aircraft Constructors | |
| Messerschmitt-Bolkow-Blohm | MBB | 61 | Aircraft Manufacturers | Non UK |
| M.B.International | MBInternational | 1 | Testing | Test Equipment |
| M.B. Metals Ltd | MBMetals | 22 | Components | Cables |
| M & B Plastics | MBPlastics | 1 | Materials | Plastics |
| M.Calderon Ltd | MCalderon | 2 | Components | Electrical |
| McAlpine Aviation | McAlpine | 10 | Air Transport | Air Charter |
| McColl's Asbestos & Rubber Co | McColl | 1 | Communications | Gaskets |
| McDonnell Douglas | McDonnelDouglas | 157 | Aircraft Manufacturers | Non UK |
| McGowan, Wild & Co | McGowanWild | 2 | Engineering Equipment | Welding |
| McGraw-Hill Publishing Co Ltd | McGrawHill | 1 | Literature | Publishers |
| McGruer Bentwood Hollow Spar Company | McGruerBentwood | 5 | Manufacturing | Components |
| MCL And Repetition Ltd | MCLRepetition | 378 | Fabrication | Fasteners |
| McMichael Radio Ltd | McMichael | 10 | Instrument Manufacturers | Test Equipment |
| McMurdo Instrument Co Ltd | McMurdo | 2 | Survival Equipment | Lifejacket Lights |
| McDonnell Douglas | MD | 1 | Aircraft Manufacturers | Non UK |
| Middle East Airlines |
MEA | 1 | Air Transport | Airlines |
| MEA Magneto Co Ltd | MEAMagneto | 1 | Components | Magnetos |
| The Mears Ear Phone Co | Mears | 1 | Avionics | Intercom |
| Mechanische Werkstaetten Neubrandenburg G.M.B.H | Mechanische | 1 | Manufacturing | Components |
| Mechanism Ltd | Mechanism | 37 | Instrument Manufacturers | Flight Instruments |
| Meerloo & Sons. John | Meerloo | 22 | Engineering Equipment | Machining |
| Meir. City Aerodrome | Meir | 1 | Airfields | |
| M.E.L.Equipment Company Ltd. The |
MEL | 1 | Avionics | Radio |
| Mendine Co | MendineCo | 6 | Materials | Adhesives |
| Mercury Truck & Tractor Co Ltd | MercuryTruck | 35 | Ground Equipment | Ground Handling |
| Mervyn Instruments | MervynInstruments | 1 | Testing | Test Equipment |
| MESH | MESH | 3 | Aircraft Manufacturers | |
| Messenger Bros Ltd | MessengerBros | 2 | Manufacturing | Sheet Metal Work |
| Messerschmitt AG | Messerschmitt | 6 | Aircraft Manufacturers | Non UK |
| Messier. British | Messier | 118 | Components | Landing Gear |
| Mestre & Blatge | MestreBlatge | 9 | Components | Tubing |
| Metachemical Processes Ltd | Metachemical | 21 | Components | De Icing |
| Metafiltration Company Ltd | Metafiltration | 8 | Engineering Equipment | Filters |
| Metalair | Metalair | 73 | Fabrication | Sheet Metal Work |
| Metal Airscrew Co | MetalAirscrew | 6 | Components | Propellers |
| Metalectric Furnaces Ltd | MetalectricFurnaces | 1 | Engineering Equipment | Furnaces |
| Metalline Aviation Lighting | Metalline | 5 | Airfields | Lighting |
| Metallisation Ltd | Metallisation | 16 | Finishes | Treatments |
| Metal Propellers Ltd | MetalPropellers | 26 | Materials | Steel |
| Metals Coating Co Ltd | MetalsCoating | 1 | Finishes | Paints |
| Metal Sections Ltd | MetalSections | 1 | Manufacturing | Sections |
| Metalstick Ltd | Metalstick | 41 | Components | Bearings |
| Meta-Sokol | MetaSokol | 1 | Aircraft Suppliers | Distributors |
| Meteorlite Ltd. A-L | Meteorlite | 2 | Manufacturing | Welding |
| Meteor Manufacturing Compnay Ltd. The | MeteorMfg | 4 | Manufacturing | Components |
| Meterflow Ltd | Meterflow | 1 | Instrument Manufacturers | Test Equipment |
| Metropolitan Plywood Company | MetropolitanPlywood | 3 | Materials | Wood |
| Metropolitan Vickers Electrical Co Ltd | Metrovick | 16 | Components | Castings |
| Mexfield Aviation (Sales) Ltd | Mexfield | 1 | Aircraft Suppliers | Distributors |
| Meyrowitz Ltd. E B | Meyrowitz | 61 | Clothing | Flying Clothing |
| M.H.Godden (Cheltenham) Ltd | MHGodden | 8 | Components | Industrial Weavers |
| M.H.H. Engineering Co Ltd | MHHEngineering | 6 | Ground Equipment | Hand Tools |
| Mica Products Ltd | Mica | 1 | Materials | Mica |
| Micanite & Insulators Co Ltd | Micanite | 3 | Materials | Paxolin |
| Michel. Aviation | Michel | 1 | Engine Manufacturers | Non UK |
| Microcell Limited | Microcell | 22 | Components | Cabin Seating |
| Middlteon Sheet Metal Co Ltd | MIddlteonSheet | 8 | Manufacturing | Sheet Metal Work |
| Midland Aeroplane Company | MidlandAeroplane | 2 | Aircraft Manufacturers | Glider |
| Midland Aeroquipment | MidlandAeroquip | 5 | Components | Castings |
| Midland Fan Co Ltd | MidlandFan | 3 | Ground Equipment | Paint Spraying |
| Midland Motor Cylinder Co Ltd | MidlandMotorCylinder | 6 | Components | Cylinders |
| Midland Motor Radiator Company.The | MidlandMotorRadiat | 1 | Components | Radiators |
| Midland Presswork Co | MidlandPresswork | 3 | Manufacturing | Presswork |
| Midland School Of Flying | MidlandSchool | 4 | Training | Flying School |
| Midland Silicones Ltd | MidlandSilicones | 1 | Materials | Rubber |
| Miesse Petrol Car Syndicate. The | Miesse | 1 | Engine Manufacturers | |
| Miles. Phillips & Powis Aircraft (Reading Ltd) | Miles | 246 | Aircraft Manufacturers | |
| Miller Aviation Ltd | Miller | 9 | Aircraft Parts | AGS |
| Mills Ltd. William | Mills | 43 | Fabrication | Castings |
| Mills Equipment Company. The | MillsEquipment | 1 | Manufacturing | Safety Belts |
| Minchin Engineering Co Ltd. The | MInchinEngineering | 2 | Manufacturing | Components |
| Mining And Chemical Products Ltd | MiningAndChemical | 20 | Chemicals | Fusible Alloys |
| Minox Ltd | Minox | 1 | Photography | Cameras |
| Mintex. British Belting & Asbestos Ltd | Mintex | 7 | Components | Brakes |
| Miralite | Miralite | 1 | Components | Pistons |
| Miscellaneous Items | Misc | 571 | Unclassified | |
| MISR Airwork S.A.E | MISR | 2 | Air Transport | Airlines |
| Mitchell Fox & Co Ltd | MitchellFox | 1 | Manufacturing | Machine Tools |
| Mitchell Hydraulics Ltd | MitchellHydraulics | 1 | Components | Hydraulics |
| Mitchell Wedgwood & Co | MitchellWedgwood | 1 | Components | AGS |
| Mitsubishi | Mitsubishi | 17 | Aircraft Manufacturers | Non UK |
| M.L Aviation Company Ltd | MLAviation | 124 | Recruitment | Drafting |
| M-L Magneto Syndicate Ltd | MLMagneto | 3 | Components | Magnetos |
| M.Mole & Son Ltd | MMole | 1 | Manufacturing | Presswork |
| Moblil. Vacuum Oil Co Ltd | Mobiloil | 85 | Lubricant Suppliers | |
| Kleemann Plastics Ltd | Models | 156 | Models | Display |
| Modern Furnaces & Stoves Ltd | ModernFurnaces | 2 | Engineering Equipment | Furnaces |
| Modern Industrial Finishes Ltd | ModernIndustrial | 3 | Finishes | Paints |
| Modern Machine Tools Ltd | ModernMachine | 1 | Manufacturing | Machine Tools |
| Modern Precision Engineers (Finchley) Ltd | ModernPrecision | 1 | Components | Avionics |
| Mollart Engineering Co | Mollart | 82 | Components | Controls |
| Monaco Motor & Engineering Co Ltd | Monaco | 4 | Engine Manufacturers | |
| Monarch Airlines Ltd | Monarch | 1 | Air Transport | Airlines |
| Monarch Engineering Co Ltd | MonarchEng | 4 | Manufacturing | Sheet Metal Work |
| Monarch Tool Co Ltd | MonarchTool | 2 | Engineering Equipment | Machine Tools |
| Mond Nickel Company Ltd. The | MondNickel | 9 | Finishes | Heat Treatments |
| Monkbridge Iron & Steel Co Ltd | Monkbridge | 2 | Manufacturing | Foundries |
| Monk Engineering Co Ltd | MonkEngineering | 7 | Fabrication | Jigs |
| Monochrome Ltd | Monochrome | 2 | Finishes | Electroplating |
| Mono-Spar Co Ltd | Monospar | 2 | Manufacturing | Aircraft |
| Monsanto | Monsanto | 12 | Chemicals | Hydraulics |
| Montgomery Smith & Co Ltd | Montgomery Smith | 2 | Engineering Equipment | Hand Tools |
| Mooney | Mooney | 12 | Aircraft Manufacturers | Non UK |
| Moore Bros Co Ltd | MooreBros | 1 | Engineering Equipment | Hand Tools |
| Moore & Wright (Sheffield) Ltd | MooreWright | 1 | Manufacturing | Tools |
| Morava | Morava | 1 | Aircraft Manufacturers | Non UK |
| Morfax Ltd | Morfax | 1 | Aeronautical Engineers | |
| Morgan Crucible Co Ltd | MorganCrucible | 5 | Materials | Carbon |
| Morgen Avco Ltd | MorgenAvco | 1 | Pilot Supplies | Navigation |
| Morris Ltd. B.O. | Morrisflex | 48 | Ground Equipment | Engineering |
| Morrisons | Morrisons | 34 | Fabrication | Contractors |
| Morris,Russell & Co Ltd | MorrisRussell | 4 | Manufacturing | Sheet Metal Work |
| Moseley & Sons Ltd. David | Moseley | 12 | Fixtures and Fittings | Cushions |
| Moss Bros & Co Ltd | MossBros | 12 | Clothing | Flying |
| Moss Brothers Aircraft Ltd | MossBrothers | 2 | Aircraft Manufacturers | |
| Moss Gear Co Ltd | MossGears | 2 | Manufacturing | Gears |
| Motoimport | Motoimport | 38 | Aircraft Suppliers | Distributors |
| Motokov | Motokov | 6 | Aircraft Manufacturers | |
| Motor Components (Coventry) Ltd | MotorComponents | 1 | Manufacturing | Machining |
| Motor Mac's Ltd | MotorMacs | 2 | Aeronautical Engineers | |
| Motorola | Motorola |
3 | Personal | Radio |
| Motorplanes Ltd | Motorplanes | 2 | Components | Propellers |
| Motor Radiator Manufacturing Co | MotorRadiator | 9 | Components | Radiators |
| Motor Radiators Ltd | MotorRadiatorS | 1 | Components | Radiators |
| Mount Cook Airlines | MountCook | 1 | Air Transport | Airlines |
| Mountford (Birm) Ltd. Fredk | Mountford | 22 | Fasteners | AGS |
| Moxons Ltd | Moxons | 1 | Airfields | Surfaces |
| Muir & Adie Ltd | MuirAdie | 2 | Engineering Equipment | Compressors |
| Muirhead & Co Ltd | Muirhead | 3 | Testing | Test Equipment |
| Mullard Ltd | Mullard | 6 | Avionics | Radio |
| Mulliner | Mulliner | 3 | Distributors | Propellers |
| Multicore Solders Ltd | Multicore | 28 | Materials | Jointing Compounds |
| Multiplex Advertising Machine Co Ltd | MultiplexAdvert | 1 | Manufacturing | Capstan Milling |
| Murad Machine Tool Co Ltd | Murad | 15 | Engineering Equipment | Machine Tools |
| Murex Welding Processes Ltd | Murex | 64 | Ground Equipment | Ground Handling |
| Murphy Radio Ltd | Murphy | 19 | Avionics | Navigation |
| Musgrave & Co Ltd | Musgarve | 4 | Factory | Air Conditioning |
| Musgrave & Co Ltd | Musgrave | 1 | Factory | Air Conditioning |
| Musgrove & Green Ltd | MusgroveGreen | 2 | Manufacturing | Sheet Metal Work |
| Mustikon Ltd | Mustikon | 3 | Wheels And Tyres | Puncture Repair |
| Myers & Co. S.J. | Myers | 9 | Engineering Equipment | Riveting |
