- Blue Portals Test Chamber 02
- Bob the Janitor
- Bomb
- Bomb/de
- Bomb/fi
- Bomb/fr
- Bomb/pt-br
- Bomb/ru
- Bombs
- Books
- Books/pt-br
- Books/ru
- Boots
- Boots (Video)
- Boots (video)
- Boots (video)/fi
- Boots (video)/ru
- Borealis
- Borealis/fi
- Borealis/fr
- Borealis/pt-br
- Borealis/ru
- Bot's Beret
- Bot's Beret/cs
- Bot's Beret/fi
- Bot's Beret/pl
- Bot's Beret/pt-br
- Bot's Beret/ru
- Bot Trust
- Bot Trust/es
- Bot Trust/pl
- Bot Trust/ru
- Bot Trust (Video)
- Bot Trust (Video)/ru
- Bot Trust (video)
- Bot Trust (video)/fi
- Bot Trust (video)/ja
- Bot Trust (video)/pl
- Bot Trust (video)/ru
- Bots
- Bots/fi
- Bots/pt-br
- Bots/ru
- Bots Beret
- Bottomless Pit
- Box Art
- Box Art/fi
- Box Art/pt-br
- Box Art/ru
- Boxes
- Breaker Room
- Bridge Constructor Portal
- Bridge Constructor Portal/es
- Bridge Constructor Portal/ru
- Bureaucrats
- Button
- Button/fi
- Button/fr
- Button/pt-br
- Button/ru
- Buttons
- Buttons/fi
- COGS FLAG
- COMPLETE PACK
- CUBE N SKULL FLAGS
- Cake
- Cake/de
- Cake/es
- Cake/fi
- Cake/fr
- Cake/pt-br
- Cake/ru
- Cake Core
- Cake Core/fi
- Cake Core/fr
- Cake Core/ru
- Cake Core/zh-hans
- Calibration Course
- Camera
- Cara Mia
- Cara Mia Addio
- Caroline
- Caroline/cs
- Caroline/es
- Caroline/fi
- Caroline/fr
- Caroline/pt-br
- Caroline/ru
- Caroline/zh-hant
- Caroline quotes
- Caroline voice lines
- Caroline voice lines/cs
- Caroline voice lines/de
- Caroline voice lines/es
- Caroline voice lines/fi
- Caroline voice lines/fr
- Caroline voice lines/pt-br
- Caroline voice lines/ru
- Cave
- Cave Johnson
- Cave Johnson/cs
- Cave Johnson/da
- Cave Johnson/es
- Cave Johnson/fi
- Cave Johnson/fr
- Cave Johnson/ja
- Cave Johnson/pt-br
- Cave Johnson/ru
- Cave Johnson/zh-hant
- Cave Johnson quotes
- Cave Johnson voice lines
- Cave Johnson voice lines/cs
- Cave Johnson voice lines/da
- Cave Johnson voice lines/de
- Cave Johnson voice lines/es
- Cave Johnson voice lines/fi
- Cave Johnson voice lines/fr
- Cave Johnson voice lines/ru
- Cave johnson
- Central AI Chamber
- Central AI Chamber/ru
- Central Core
- Central Core/fi
- Challenge Mode
- Chamber
- Chamber lock
- Chamberlock
- Chamberlock/cs
- Chamberlock/de
- Chamberlock/es
- Chamberlock/fi
- Chamberlock/fr
- Chamberlock/ja
- Chamberlock/ko
- Chamberlock/pl
- Chamberlock/pt-br
- Chamberlock/ru
- Chambers
- Characters
- Characters/cs
- Characters/de
- Characters/es
- Characters/fi
- Characters/fr
- Characters/hu
- Characters/ja
- Characters/ko
- Characters/nl
- Characters/pl
- Characters/pt-br
- Characters/ru
- Characters/sv
- Characters/zh-hans
- Characters/zh-hant
- Chell
- Chell/cs
- Chell/es
- Chell/fi
- Chell/fr
- Chell/ja
- Chell/ko
- Chell/pl
- Chell/pt-br
- Chell/ru
- Chell/zh-hans
- CinTech
- Circuit Breaker
- Circuit Breaker/es
- Circuit Breaker/fi
- Circuit Breaker/fr
- Circuit Breaker/ko
- Circuit Breaker/ru
- Classified
- Cleansing Gel
- Cleansing Gel/ru
- Co-Op
- Co-op
- Co-op/cs
- Co-op/es
- Co-op/fi
- Co-op/fr
- Co-op/pl
- Co-op/pt-br
- Co-op/ru
- Cogs Flag
- Cogs Flag/fi
- Cogs Flag/pl
- Cogs Flag/pt-br
- Cogs Flag/ru
- Collaborative Disposition Test
- Collaborative Disposition Test/fi
- Collaborative Disposition Test/ko
- Collaborative Disposition Test/pt-br
- Collaborative Disposition Test/ru
- Combine OverWiki
- Comic
- Commentary
- Community content
- Community content/fi
- Community content/fr
- Community content/pl
- Community content/pt-br
- Community content/ru
- Companion Cube
- Companion Cube/fr
- Companion Cube/ru
- Companion cube
- Complete Bundle
- Complete Pack
- Complete Pack/fi
- Complete Pack/fr
- Complete Pack/pt-br
- Complete Pack/ru
- Complete Pack (Part 2)
- Complete Pack (Part 2)/fi
- Complete Pack (Part 2)/pt-br
- Complete Pack (Part 2)/ru
- Concept art
- Concept art/fi
- Concept art/pt-br
- Concept art/ru
- Confianza entre Bots
- Contraption Cube
- Controls
- Conversion Gel
- Conversion Gel/es
- Conversion Gel/fi
- Conversion Gel/fr
- Conversion Gel/ko
- Conversion Gel/ru
- Conversion Gel/zh-hant
- Coop
- Cooperative Testing Initiative
- Cooperative Testing Initiative/Calibration Course
- Cooperative Testing Initiative/Calibration Course/link
- Cooperative Testing Initiative/Calibration Course/link with introduction
- Cooperative Testing Initiative/Calibration Course/mention
- Cooperative Testing Initiative/Course 1: Team Building
- Cooperative Testing Initiative/Course 1: Team Building/Course 1: Mobility Gels/01 Doors
- Cooperative Testing Initiative/Course 1: Team Building/Course 1: Mobility Gels/01 Doors/fr
- Cooperative Testing Initiative/Course 1: Team Building/Course 1: Mobility Gels/02 Buttons
- Cooperative Testing Initiative/Course 1: Team Building/Course 1: Mobility Gels/02 Buttons/fr
- Cooperative Testing Initiative/Course 5: Mobility Gels
- Cooperative Testing Initiative/Course 5: Mobility Gels/08 Vault Entrance
- Cooperative Testing Initiative/Course 5: Mobility Gels/08 Vault Entrance/link
- Cooperative Testing Initiative/Course 5: Mobility Gels/08 Vault Entrance/link with introduction
- Cooperative Testing Initiative/Course 5: Mobility Gels/08 Vault Entrance/mention
- Cooperative Testing Initiative/Credits
- Cooperative Testing Initiative/es
- Cooperative Testing Initiative/fi
- Cooperative Testing Initiative/ru
- Core
- Core Transfer Receptacle
- Core voice lines
- Core voice lines/cs
- Core voice lines/de
- Core voice lines/es
- Core voice lines/fi
- Core voice lines/fr
- Core voice lines/ko
- Core voice lines/pt-br
- Core voice lines/ru
- Core voice lines/zh-hans
- Cores
- Cores/cs
- Cores/de
- Cores/es
- Cores/fi
- Cores/fr
- Cores/hu
- Cores/ja
- Cores/ko
- Cores/pl
- Cores/ru
- Cores/zh-hans
- Cores voice lines
- Corrupt personality core lines
- Corrupted Cores
- Craig
- Crap Turrets
- Crown
- Crusher
- Crusher/de
- Crusher/fi
- Crusher/fr
- Crusher/ru
- Crushers
- Crushers/fi
- Crushers/ko
- Cube
- Cube/es
- Cube/fi
- Cube/fr
- Cube/ru
- Cube N Skull Flags
- Cube N Skull Flags/es
- Cube N Skull Flags/fi
- Cube N Skull Flags/pt-br
- Cube N Skull Flags/ru
- Cube n skull flag
- Cubes
- Cubes/de
- Cubes/es
- Cubes/fi
- Cubes/fr
- Cubes/pl
- Cubes/pt-br
- Cubes/ru
- Cubes/zh-hant
- Curiosity Core
- Curiosity Core/es
- Curiosity Core/fi
- Curiosity Core/fr
- Curiosity Core/ru
- Curiosity Core/zh-hans
- Czapka Mann Co.
- Czapki
- DEFENSE GRID FLAG
- DLC
- Deadly Laser
- Deadly Neurotoxin
- Deadly laser
- Death Fizzler
- Death Fizzlers
- December 04, 2014 Patch
- December 04, 2014 Patch/es
- December 04, 2014 Patch/pt-br
- December 04, 2014 Patch/ru
- December 08, 2014 Patch (Portal)
- December 08, 2014 Patch (Portal)/es
- December 08, 2014 Patch (Portal)/ru
- December 15, 2022 Patch
- December 15, 2022 Patch/ru
- December 4, 2014 Patch
- December 4, 2014 Patch/es
- December 4, 2014 Patch/pt-br
- December 4, 2014 Patch/ru
- December 7, 2016 Patch (The Lab)
- December 7, 2016 Patch (The Lab)/ru
- December 8, 2014 Patch (Portal)
- December 8, 2014 Patch (Portal)/es
- December 8, 2014 Patch (Portal)/ru
- Default keybinds
- Default keybinds/de
- Default keybinds/fi