M
- Madame Rouge (alias Laura DeMille)
- Magenta
- Magno (Golden Age)
- Magno (Modern Age)
- Major Disaster
- Mammoth
- Man-Bat
- Manfred Mota
- Manticore (member of the Global Guardians)
- Más y Menos (see also Teen Titans animated series)
- Matter Master
- Maxi-Man
- Maxwell Lord
- Max Mercury
- Mayflower
- Meloni Thawne
- Mento
- Minddancer
- Mindboggler
- Mind-Grabber Kid
- Mirage
- Miss America
- Mist I and II
- Mister 104
- Mister Bones
- Mister Element I and II
- Mister ESPer
- Mister Freeze
- Mister Nobody
- Molecule
- Mongrel (member of the Blood Pack)
- Monsoon
- Morozko (member of Soyuz)
- Muhammad X
- Multi-Man
- Multiplex
- Mystek
Read more about this topic: List Of Metahumans In DC Comics