The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Call of Duty (Series) (11 members)
- Call of Juarez (Series) (3 members)
- Camera input: PS Eye (Config) (3 members)
- Camera settings: Qt (Config) (3 members)
- Candygun Games (Developer) (2 members)
- Capcom (Developer) (33 members)
- Capcom (Publisher) (66 members)
- Capybara Games (Developer) (2 members)
- Capybara Games (Publisher) (1 member)
- Card game (Genre) (16 members)
- Castlevania (Series) (4 members)
- Casual Brothers (Developer) (1 member)
- Casual Brothers (Publisher) (1 member)
- Cattle Call (Developer) (1 member)
- Cauldron (Developer) (7 members)
- Cauldron HQ (Developer) (3 members)
- Cave (Developer) (1 member)
- Cavia (Developer) (3 members)
- Cellar Door Games (Developer) (1 member)
- Cellar Door Games (Publisher) (1 member)
- Cellius (Developer) (1 member)
- Certain Affinity (Developer) (1 member)
- Cherry Pop Games (Developer) (1 member)
- Cherry Pop Games (Publisher) (1 member)
- Chunsoft (Developer) (1 member)
- Chunsoft (Publisher) (1 member)
- Cipher Prime (Developer) (2 members)
- Cipher Prime (Publisher) (1 member)
- City Interactive (Developer) (5 members)
- City Interactive (Publisher) (5 members)
- Clap Hanz (Developer) (3 members)
- Class of Heroes (Series) (2 members)
- ClassiC Shikoukairo (Developer) (1 member)
- Clever Beans (Developer) (1 member)
- Climax Studios (Developer) (2 members)
- Clocks scale (Config) (0 members)
- Co-op (Game mode) (369 members)
- Code Mystics (Developer) (1 member)
- Codeglue (Developer) (1 member)
- Codemasters (Developer) (17 members)
- Codemasters (Publisher) (27 members)
- Coffee Stain Studios (Developer) (2 members)
- Cohort Studios (Developer) (6 members)
- ColdWood Interactive (Developer) (3 members)
- Cold Beam Games (Developer) (1 member)
- Cold Beam Games (Publisher) (1 member)
- Combat flight simulator (Genre) (22 members)
- Comcept (Developer) (1 member)
- Command & Conquer (Series) (2 members)
- Compile Heart, Red Entertainment (Publisher) (1 member)