| Marginal #4: Kiss kara Tsukuru Big Bang | January 12, 2017 | — | — |
| Marginal Prince | October 1, 2006 | — | 13 |
| Maria Holic | January 4, 2009 | — | 24 |
| Maria the Virgin Witch | January 11, 2015 | — | 12 |
| Maria-sama ga Miteru | January 7, 2004 | TV Tokyo | 44 |
| Marie & Gali | March 31, 2009 | NHK Educational TV | — |
| Marika's Love Meter Malfunction | April 6, 2026 | — | 8 |
| Marine Boy | October 6, 1966 | Fuji Television, TBS Television | — |
| Marmalade Boy | March 13, 1994 | TV Asahi | 76 |
| Marriagetoxin | April 7, 2026 | — | 13 |
| Mars Daybreak | April 1, 2004 | — | 26 |
| Mars Red | April 6, 2021 | — | 13 |
| Martian Successor Nadesico | October 1, 1996 | TV Tokyo | 26 |
| Marude Dameo | November 2, 1991 | — | 47 |
| Marvel Anime | October 1, 2010 | Animax, G4 | 48 |
| Marvel Disk Wars: The Avengers | April 2, 2014 | — | 51 |
| Marvel Future Avengers | July 22, 2017 | — | — |
| Marvelous Melmo | October 3, 1971 | — | 26 |
| Masamune Datenicle | May 2, 2016 | — | 6 |
| Masamune-kun's Revenge | January 5, 2017 | — | 24 |
| Mashin Creator Wataru | January 12, 2025 | TX Network | — |
| Mashin Hero Wataru | April 15, 1988 | Nippon Television | 45 |
| Mashin Hero Wataru 2 | March 9, 1990 | — | 46 |
| Mashin Hero Wataru The Seven Spirits of Ryujinmaru | — | — | — |
| Mashiroiro Symphony | October 5, 2011 | — | 12 |
| Mashle | April 8, 2023 | — | 24 |
| Massugu ni Ikō: Go Forward. | August 18, 2003 | — | 9 |
| Master Keaton | October 6, 1998 | Nippon Television | 24 |
| Master of Epic: The Animation Age | 2007 | — | — |
| Master of Martial Hearts | October 29, 2008 | — | 5 |
| Matchless Raijin-Oh | April 3, 1991 | TV Tokyo | 51 |
| Matoi the Sacred Slayer | October 4, 2016 | — | 12 |
| Matsurika Kanriden | January 2027 | — | — |
| May I Ask for One Final Thing? | October 4, 2025 | — | 13 |
| Maya the Honey Bee | April 1, 1975 | TV Asahi | 104 |
| Mayo Chiki! | July 7, 2011 | TBS Television | 13 |
| Mayoi Neko Overrun! | April 6, 2010 | — | 13 |
| Mayonaka Punch | July 8, 2024 | — | 12 |
| Maze | July 24, 1996 | — | 2 |
| Maze | April 2, 1997 | — | 25 |
| Mazinger Edition Z: The Impact! | April 4, 2009 | — | — |
| Mazinger Z | December 3, 1972 | Fuji Television | 92 |
| Me & Roboco | December 4, 2022 | TX Network | 28 |
| Me and the Alien MuMu | April 10, 2025 | — | 24 |
| Mebius Dust | July 9, 2026 | — | 12 |
| Mech Cadets | August 10, 2023 | Netflix | 10 |
| Mechander Robo | March 3, 1977 | — | 35 |
| Mechanical Arms | October 4, 2024 | — | 12 |
| Mechanical Marie | October 5, 2025 | — | 12 |
| Medabots | July 2, 1999 | — | 52 |
| Medaka Box | April 5, 2012 | — | 12 |
| Medaka Kuroiwa Is Impervious to My Charms | January 7, 2025 | TX Network | 12 |
| Medalist | January 5, 2025 | — | 22 |
| Mega Man Star Force | October 5, 2006 | TV Tokyo | — |
| Mega Man: Fully Charged | August 5, 2018 | Cartoon Network, WildBrainTV | 26 |
| Megalobox | April 6, 2018 | — | 26 |
| MegaMan NT Warrior | March 4, 2002 | — | 209 |
| Meganebu! | October 6, 2013 | — | 12 |
| Megaton Musashi | October 1, 2021 | — | 28 |
| Megazone 23 | — | — | — |