The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Western (0 members)
- Western Asia (8 members)
- Western University (10 members)
- WetLand (12 members)
- Wetland (3 members)
- Wetlands (3 members)
- Wheelchairs (4 members)
- Widget templates (8 members)
- Widgets (0 members)
- Wika (1 member)
- Wiki Green (4 members)
- Wikis (39 members)
- Wikis for human development (5 members)
- Wikis for international development (31 members)
- Wikis for social change (8 members)
- Wikis for sustainability (50 members)
- Wiltshire (2 members)
- Wind power (58 members)
- Windbelt (2 members)
- Windbelts (5 members)