The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Self (7 members)
- Self-control (0 members)
- Serenity Concord (7 members)
- Serenity Concord Territory (9 members)
- Set index article templates (1 member)
- Sex and sexuality navigational boxes (1 member)
- Sidebars with styles needing conversion (9 members)
- Sigma Tamelos Sector (12 members)
- Social concepts (1 member)
- Social ideologies (1 member)
- Social psychology (2 members)
- Social theories (1 member)
- Sociological theories (1 member)
- Solas Tempus (55 members)
- Solas Tempus Characters (40 members)
- Solas Tempus Military Actions (2 members)
- Solas Tempus Non-Player Characters (55 members)
- Solas Tempus Reports (8 members)
- Solas Tempus Vessels and Facilities (84 members)
- Sources of Inspiration (3 members)
- Space Anomalies (7 members)
- Space Sectors (22 members)
- Space Station Designs (10 members)
- Space Stations (25 members)
- Space Vessel (1 member)
- Space Vessel Designs (69 members)
- Space Vessels (104 members)
- Special Abilities (7 members)
- Spells (7 members)
- Star Systems (57 members)
- Star Wars (0 members)
- Starfleet (4 members)
- Starfleet Characters (3 members)
- Starfleet Non-Player Characters (4 members)
- Starfleet Vessels and Facilities (9 members)
- Stub message templates (1 member)
- Stubs (58 members)
- Subtemplates of WPBannerMeta (1 member)
- Sumutlis Sector (5 members)
- Super Powers (0 members)
- Swiss writer navigational boxes (1 member)
- Søren Kierkegaard (1 member)
- Talk Pages (76 members)
- Talk header templates (1 member)
- Talk message boxes (3 members)
- Talk namespace templates (1 member)
- Tau Majestius Sector (7 members)
- Technology (3 members)
- Template documentation (15 members)
- Template documentation pages (13 members)