The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Union songs (2 members)
- United Nations (4 members)
- United States (0 members)
- United States Army personnel (2 members)
- United States Attorneys for the District of Columbia (1 member)
- United States Congress (1 member)
- United States Navy personnel (1 member)
- United States Secretaries of State (4 members)
- United States of America (29 members)
- Universities (1 member)
- Urban design (1 member)
- Userboxes with insufficient color contrast (6 members)
- Utopian socialism (7 members)
- Utopian socialists (4 members)
- Value (4 members)
- Venezuela (1 member)
- Venezuelan revolutionaries (3 members)
- Venezuelans of Colombian descent (1 member)
- Vice Presidents of the United States (4 members)
- Victims of assassination (12 members)