| MarsUnderground | Developer | |
| Marshal Ruffy | Developer | |
| Marshall Cannon | Developer | |
| MarshallWorks | Developer | |
| Marshlight Software | Developer | |
| Marshmallow9 | Developer | |
| Marshy | Developer | |
| Marslit Games | DeveloperPublisher | |
| Marson | Developer | |
| Marsu | Developer | |
| Martech | DeveloperPublisher | |
| Martech Games | DeveloperPublisher | |
| Martech Software | DeveloperPublisher | |
| Martelo | Developer | |
| Marten Jonsson | Developer | |
| Martenfur | Developer | |
| Martha | Developer | |
| Martha S.E.E | Developer | |
| Martholemy | Developer | |
| MartholemyLabs | Developer | |
| Marti Wong | Developer | |
| Martial Hesse-Dreville | Developer | |
| Martian's Parlor Entertainment | Developer | |
| MartianGames | Developer | |
| Martim Freitas | Developer | |
| MartimDev | Developer | |
| Martin | Developer | |
| Martin Džejky Jakubik | Developer | |
| Martin Ao | Developer | |
| Martin Asteasuain | Developer | |
| Martin Beierling | Developer | |
| Martin Bussy-Pâris | Developer | |
| Martin Calujek | Developer | |
| Martin Cohen | Developer | |
| Martin Delemotte | Developer | |
| Martin Donald | Developer | |
| Martin Galway | Developer | |
| Martin Harris | Developer | |
| Martin Haye | DeveloperPublisher | |
| Martin Holland | Developer | |
| Martin Hooley | Developer | |
| Martin Isla | Developer | |
| Martin Jacob | Developer | |
| Martin Magni | Developer | |
| Martin Magnusson | Publisher | |
| Martin Marietta | Publisher | |
| Martin McDonald | Developer | |
| Martin Nerurkar | Developer | |
| Martin Piper | Developer | |
| Martin Salomon | Developer | |
| Martin Schweiger | Developer | |
| Martin Senges | Developer | |
| Martin Severn | Developer | |
| Martin Software Productions | Publisher | |
| Martin Starešinčić | Developer | |
| Martin Tale | Developer | |
| Martin Ulrich | Developer | |
| Martin Walker | Developer | |
| Martin Ward | Developer | |
| MartinBousquet | Developer | |
| MartinSchubert | Developer | |
| MartinTristan | Developer | |
| Marty Green | Developer | |
| Martyn | Developer | |
| Martyn Hartley | Developer | |
| Martynas | Developer | |
| Martí Guillot Torrodà | Developer | |
| Martín Salvador Sosa | Developer | |
| Marubeni | Developer | |
| Marudice | Developer | |
| Marumittu | Developer | |
| Marvel | Publisher | |
| Marvel Soft | Publisher | |
| Marvelous | DeveloperPublisher | |
| Marvelous AQL | DeveloperPublisher | |
| Marvelous Entertainment | DeveloperPublisher | |
| Marvelous Entertainment (JP) | Publisher | |
| Marvelous EntertainmentJP | Publisher | |
| Marvelous Europe | Publisher | |
| Marvelous First Studio | Developer | |
| Marvelous Inc. | DeveloperPublisher | |
| Marvelous Interactive | DeveloperPublisher | |
| Marvelous Interactive (Japan) | Publisher | |
| Marvin Glass and Associates | Developer | |
| Marx The Modder | Developer | |
| Marxtodon | Developer | |
| Mary | Developer | |
| Mary Arroz | Developer | |
| Mary K | Developer | |
| Mary McK | Developer | |
| Mary T. | Developer | |
| Mary-Margaret | Developer | |
| MaryMajesty | Developer | |
| MaryTeam | Developer | |
| Marzar | Developer | |
| MasTho0128 | Developer | |
| MasangSoft | Developer | |
| Masatoko Games | DeveloperPublisher | |
| Masaya | DeveloperPublisher | |
| Masaya (JP) | Publisher | |