The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Sidhe (Developer) (5 members)
- Sidhe (Publisher) (1 member)
- Sidhe Interactive (Developer) (1 member)
- Sierra Entertainment (Publisher) (1 member)
- Sigma Team (Developer) (1 member)
- Silence all logs: On (Config) (2 members)
- Silent Hill (Series) (3 members)
- Silicon Knights (Developer) (1 member)
- Silicon Studio (Developer) (2 members)
- SilverStar (Developer) (2 members)
- SilverStar (Publisher) (3 members)
- Silverball Studios (Developer) (1 member)
- Simulation (Genre) (16 members)
- SingStar (Series) (28 members)
- Single-player (Game mode) (1,475 members)
- Size Five Games (Developer) (1 member)
- Skate (Series) (3 members)
- SkyFallen Entertainment (Developer) (1 member)
- Skylanders (Series) (6 members)
- Slang (Publisher) (1 member)
- Slant Six Games (Developer) (3 members)
- Sledgehammer Games (Developer) (2 members)
- Sleep timers accuracy: As Host (Config) (24 members)
- Sleep timers accuracy: Usleep Only (Config) (1 member)
- Slightly Mad Studios (Developer) (3 members)
- Slitherine (Developer) (1 member)
- Slitherine (Publisher) (1 member)
- Sly Cooper (Series) (3 members)
- SmackDown vs. Raw (Series) (8 members)
- Smartphone Labs LLC (Publisher) (1 member)
- Sniper: Ghost Warrior (Series) (2 members)
- Sniper Elite (Series) (2 members)
- Snowblind Studios (Developer) (1 member)
- Snowboarding (Genre) (2 members)
- Social simulation (Genre) (2 members)
- Soedesco (Publisher) (1 member)
- Soldner-X (Series) (2 members)
- Sonic Team (Developer) (8 members)
- Sonic Team USA (Developer) (1 member)
- Sonic the Hedgehog (Series) (12 members)
- Sony Computer Entertainment (Publisher) (249 members)
- Sony Online Entertainment (Developer) (4 members)
- Sony Online Entertainment (Publisher) (24 members)
- SoulCalibur (Series) (4 members)
- Souls (Series) (3 members)
- SouthPeak Games (Publisher) (3 members)
- South Park (Series) (1 member)
- Southend Interactive (Developer) (3 members)
- Space Monkey International (Developer) (1 member)
- Spark Unlimited (Developer) (4 members)