The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- South Sudan (1 member)
- Southeast Asia (17 members)
- Southern Africa (13 members)
- Southern Asia (13 members)
- Southern Europe (32 members)
- Southest Asia (1 member)
- Sovereignty (1 member)
- Spain (19 members)
- Spanish Civil War (4 members)
- Sports (1 member)
- Squatter Uprisings (4 members)
- Squatting (19 members)
- Sri Lanka (3 members)
- States (72 members)
- Statism (2 members)
- Strategies (3 members)
- Strike (1 member)
- Strike Wave (1 member)
- Strike Waves (1 member)
- Strikes (39 members)
- Student Strikes (2 members)
- Student Uprisings (1 member)
- Sudan (2 members)
- Sweden (11 members)
- Switzerland (1 member)
- Syndicalism (5 members)
- Syndicalists (1 member)
- Syria (4 members)
- Syrian Civil War (1 member)
- Taiwan (2 members)
- Tanzania (1 member)
- Teachers (3 members)
- Technology (1 member)
- Template documentation (26 members)
- Templates (27 members)
- Templates/Infobox (8 members)
- Templates/Navbox (1 member)
- Templates/Quote (1 member)
- Terrorism (4 members)
- Terrorists (1 member)
- Thailand (3 members)
- The Irrational in Politics (2 members)
- Timelines (43 members)
- Tonga (1 member)
- Trade Union Federations (5 members)
- Trade Unionism (1 member)
- Trade Unionists (4 members)
- Trade Unions (6 members)
- Transgender People (1 member)
- Transportation (4 members)