Atualização:
- Activision Blizzard studios:
- Activision Shanghai: support studio
- Beenox: support studio, supporting Call of Duty and Crash Bandicoot
- Blizzard Team 1: Starcraft
- Blizzard Team 2: World of Warcraft
- Blizzard Team 3: Diablo
- Blizzard Team 4: Overwatch
- Blizzard Team 5: Hearthstone
- Blizzard Albany: Formerly Vicarious Visions, support studio for Diablo
- Demonware: support studio
- Digital Legends Entertainment: support studio
- High Moon Studios: support studio, supporting Call of Duty
- Infinity Ward: primary Call of Duty developer, known for Modern Warfare, Infinite Warfare, Warzone
- King: mobile developer, known for Candy Crush
- Radical Entertainment: support team, supporting Destiny
- Raven Software: support team, supporting Call of Duty
- Sledgehammer Games: primary Call of Duty developer, known for Advanced Warfare, WWII, Vanguard
- Solid State Entertainment: Call of Duty mobile
- Toys for Bob: Crash Bandicoot, Spyro. Also supporting Call of Duty: Warzone
- Treyarch: primary Call of Duty developer, known for World at War, Black Ops
- Vicarious Visions: Blizzard support studio
- Bethesda Zenimax studios:
- Alpha Dog Games: mobile developer, known for MonstroCity and WraithBorne
- Arkane Studios Austin & Lyon: Deathloop, Dishonored, Prey, Redfall
- Bethesda Game Studios: The Elder Scrolls, Fallout, Starfall
- id Software: Doom
- MachineGames: Wolfenstein, Indiana Jones
- Roundhouse Studios: new studio, formed in Nov 2019, consisting of former Prey developers
- Tango Gameworks: The Evil Within, Ghostwire: Tokyo, Hi-Fi Rush
- ZeniMax Online Studios: The Elder Scrolls Online
- Xbox's original 15 first-party developers:
- 343 Industries: Halo Infinite
- The Coalition: Gears of War franchise
- Compulsion Games: Contrast, We Happy Few, South of Midnight
- Double Fine Productions: Broken Age, Psychonauts 2, Headlander, Costume Quest, Grim Fandango Remastered, Day of the Tentacle Remastered
- The Initiative: Perfect Dark
- inXile Entertainment: Wasteland 3, The Bard's Tale franchise, Clockwork Revolution
- Mojang Studios: Minecraft franchise, Minecraft Legends, Minecraft Dungeons
- Ninja Theory: Hellblade 2, Enslaved: Odyssey to the West, Project Mara
- Obsidian Entertainment: The Outer Worlds, Avowed, Grounded, Pentiment
- Playground Games: Fable, Forza Horizon franchise
- Rare: Sea of Thieves, Everwild
- Turn10 Studios: Forza Motorsport franchise
- Undead Labs: State of Decay franchise
- World's Edge: Age of Empires franchise
- Xbox Game Studios Publishing: Battletoads, Flight Simulator, Gears Tactics, Ori, Tell Me Why, in other words, 2nd-party publishing deals