The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- JIVV (10 members)
- Jaies (1 member)
- Jared (6 members)
- Jekyle (8 members)
- Jetrotal (1 member)
- John Ruiz (3 members)
- Jojogape (5 members)
- Juda (24 members)
- K0OdntepKs (2 members)
- KKO (1 member)
- Kaite20 (0 members)
- Kappa (59 members)
- Konaki (4 members)
- Kong (15 members)
- Kontentsu (270 members)
- Kubotsuki's Nexus Worlds (0 members)
- Kubotsuki's Worlds (79 members)
- Kubotsuki BGM (1 member)
- Kubotsuki Screenshots (1 member)
- Kuraud (95 members)
- Kurokagi (18 members)
- Kuroku (33 members)
- LSD (29 members)
- Lakes (1 member)
- Led (2 members)
- Lemniscate (25 members)
- Light (27 members)
- Location templates (7 members)
- Locations (3,364 members)
- Locations with Wake-Up Events (3 members)
- Luok (5 members)
- Lysenthe (2 members)
- MadameMimic (8 members)
- Madotsuki images (95 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)
- MedicineMan1920 (1 member)
- Meena (1 member)
- Messier (5 members)
- Mikan Muzou (3 members)
- Mikan Muzou Characters (1 member)
- Mikan Muzou Guides (4 members)