The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Mooncaller (1 member)
- Moriwo (66 members)
- Mosenite (42 members)
- Multi-page Locations (12 members)
- Muma Rope (4 members)
- Muma Rope Characters (1 member)
- Muma Rope First Steps Worlds (3 members)
- Muma Rope Guides (5 members)
- Muma Rope Locations (72 members)
- Muma Rope Screenshots (1 member)
- Murasaki no Yume (4 members)
- MymeType (14 members)
- N3 (50 members)
- Nabisae (27 members)
- NacreMoon (31 members)
- Nadeko (12 members)
- Nakatsu (0 members)
- Namedude (7 members)
- Nantai (182 members)
- Natl (58 members)
- Navbox templates (0 members)
- Navigation templates (9 members)
- Needs Documentation (0 members)
- Needs Information (263 members)
- Needs documentation (37 members)
- Nekhnona (3 members)
- Nexus0.10 (5 members)
- Nexus Worlds (12 members)
- Nightmare (6 members)
- Noahrav (4 members)
- Noildoof (136 members)
- Noindexed pages (9 members)
- NostAlgic (3 members)
- NostAlgic Characters (1 member)
- NostAlgic Guides (5 members)
- NostAlgic Locations (25 members)
- NostAlgic Nexus Worlds (4 members)
- NostAlgic Screenshots (4 members)
- Notice images (1 member)
- Notice templates (9 members)
- Novel Images (9 members)
- Nuaah (142 members)
- Nulsdodage (8 members)
- Octave (43 members)
- Olm (2 members)
- Oneirokamara (50 members)
- Onychophorum (2 members)
- Open for Cross-Author Connections (107 members)
- Openbreeze (6 members)
- Orchidmantis (38 members)