M
- MacClatchie
- Macomber Avis Engine Co
- MAN-Rolls-Royce
- Manfred Weiss
- Manly
- Mantovani
- Marchetti
- Marlin-Rockwell
- Marquardt Corporation
- Martin Motors Co
- Maru
- Maximotor
- Maybach — Germany
- Mayo
- McCulloch Motors — U.S.
- McDonnell
- McDowell
- Mead
- Mekker
- Menasco Motor Company — U.S.
- Mercedes
- Mercedes-Benz — Germany
- Métallurgique
- Meteor
- Meteormotor
- Metropolitan-Vickers
- Metropolitan-Vickers — UK
- Metz
- Michigan
- Microturbo — France
- Miese
- Mikulin - Russia/Soviet Union
- Mikulin-Stechkin
- Milwaukee Tank
- Mistral Engine Company - Switzerland
- Mitsubishi Aircraft Company — Japan
- Lambert Engine Division
- Morehouse
- Mors
- Motor Sich - Ukraine
- Oberursel — Germany
- Motorlet
- Mozhaiskiy
- MTR
- MTR (MTU/Turbomeca/Rolls-Royce) (European)
- MTU Aero Engines — Germany
- Mudry
- Murray-Willat
Read more about this topic: List Of Aircraft Engine Manufacturers