The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Steam games (17 members)
- Stubs (1 member)
- Super Smash Bros. Brawl (2 members)
- Super Smash Bros. Ultimate (1 member)
- Super Smash Bros. for Nintendo 3DS and Wii U (1 member)
- Super forms (2 members)
- Table templates (1 member)
- Tails' creations (1 member)
- Tails Adventure (1 member)
- Talk header templates (1 member)
- Talk namespace templates (1 member)
- Team Sonic Racing (3 members)
- Television table cell templates (2 members)
- TemplateData (3 members)
- Template Convert (1 member)
- Template documentation (92 members)
- Template documentation pages (1 member)
- Template namespace templates (18 members)
- Template test cases (2 members)
- Templates (35 members)
- Templates based on the String Lua module (2 members)
- Templates for redirects from a modification of the target name (1 member)
- Templates for redirects from alternative names (1 member)
- Templates for redirects resulting from merges or moves (1 member)
- Templates generating microformats (1 member)
- Templates that add a tracking category (1 member)
- Templates that are not mobile friendly (1 member)
- Templates using ParserFunctions (4 members)
- Templates using TemplateData (37 members)
- Templates using TemplateStyles (4 members)
- Templates with no visible output (1 member)
- Templates with partial table wikitext (1 member)
- Text color templates (7 members)
- The Murder of Sonic the Hedgehog (1 member)
- Thieves (3 members)
- Transformations (1 member)
- Transwiki guide (4 members)
- Typing-aid templates (5 members)
- Unified table cell templates (7 members)
- Unknown namespace redirect templates (1 member)
- Video game companies (6 members)
- Villains (3 members)
- Wii U games (2 members)
- Wii Virtual Console games (4 members)
- Wii games (6 members)
- WikiProject Redirect templates (2 members)
- Wikidata modules (1 member)
- Wikipedia-specific image insertion templates (1 member)
- Wikipedia XHTML tag-replacing templates (5 members)
- Wikipedia archived wrapper templates (2 members)