The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Uneven Dream Screenshots (1 member)
- Unused (76 members)
- Uroyu (1 member)
- Uwa (6 members)
- Uwonozoki (16 members)
- VANEGI (8 members)
- Victikirby (1 member)
- Videos (120 members)
- Vivi (3 members)
- VoxlAlien (3 members)
- WXeoWvpbbM (6 members)
- Walk Cycles (62 members)
- Wataru (183 members)
- Widdershins (2 members)
- Widgets (1 member)
- Wiki-dependent (7 members)
- Wiki icons (1 member)
- Wikis (20 members)
- Wooglee (2 members)
- World Map Galleries (17 members)
- Xen (1 member)
- YNOproject (3 members)
- YNOproject Badges (20 members)
- Yarshmellow (4 members)
- Yasakoten (7 members)
- Yawaraka (2 members)
- Yeris (50 members)
- Yuki-Hitsuji (5 members)
- YumeWiki (6 members)
- Yume 2kki (13 members)
- Yume 2kki Annotated Maps (7 members)
- Yume 2kki Authors (106 members)
- Yume 2kki BGM (38 members)
- Yume 2kki Characters (48 members)
- Yume 2kki Collectables (23 members)
- Yume 2kki Contributors (4 members)
- Yume 2kki Effect NPCs (21 members)
- Yume 2kki Effects (2 members)
- Yume 2kki Guides (63 members)
- Yume 2kki Hub Worlds (30 members)
- Yume 2kki In Development (302 members)
- Yume 2kki Library Images (1 member)
- Yume 2kki Locations (1,219 members)
- Yume 2kki Locations with Wake-Up Events (68 members)
- Yume 2kki Maps (8 members)
- Yume 2kki Menu Theme Previews (1 member)
- Yume 2kki Nexus Worlds (28 members)
- Yume 2kki Picture Files (1 member)
- Yume 2kki Removed Content (31 members)
- Yume 2kki Screenshots (71 members)