The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Madoxy (2 members)
- Maengo (1 member)
- Maintenance (15 members)
- Makitsuki's Worlds (23 members)
- Manga images (80 members)
- Maple (37 members)
- Maps (51 members)
- Maptsuki (92 members)
- MartiN0304 (1 member)
- Marty281 (3 members)
- Mayapon (12 members)
- Meena (1 member)
- Messier (5 members)
- Mikan Muzou (4 members)
- Mikan Muzou Characters (1 member)
- Mikan Muzou Guides (5 members)
- Mikan Muzou Locations (55 members)
- Mikan Muzou Nexus Worlds (6 members)
- Mike (24 members)
- Milica (1 member)
- MillieAmp (20 members)
- Minichibis (2 members)
- Misc Images (208 members)
- Missing Author (1 member)
- Missing BGM (366 members)
- Missing BGM author (0 members)
- Missing Location (9 members)
- Missing Map ID (15 members)
- Missing Role (9 members)
- Missing Version Added (699 members)
- Missing infobox image (2 members)
- Missing speed (5 members)
- Mitzyrie (10 members)
- Mizkura (3 members)
- Moerani (1 member)
- Mokaccino (10 members)
- Mooncaller (1 member)
- Moriwo (66 members)
- Mosenite (55 members)
- Mount Hibiki (3 members)
- Mount Shrine (4 members)
- Multi-page Locations (12 members)
- Muma Rope (5 members)
- Muma Rope Characters (1 member)
- Muma Rope First Steps Worlds (3 members)
- Muma Rope Guides (6 members)
- Muma Rope Locations (78 members)
- Muma Rope Screenshots (1 member)
- Murasaki no Yume (6 members)
- MymeType (14 members)