Microsoft Game Studios (MGS), branded with current logo and moniker in 2002 (formerly the Microsoft Game Division), is a wholly owned subsidiary of Microsoft Corp. which develops and publishes video games for Windows-based PCs and the Xbox and Xbox 360 video game consoles. MGS publishes games for several Microsoft-owned first-party developers, including Bungie Studios and Rare Ltd.. MGS also publishes games created by third-party developers, such as Bioware and Bizarre Creations.

In 2001 Microsoft Game Studios bought Bungie Studios.

In August 2002, MGS acquired Rare from Nintendo and the Stamper brothers, who owned 49% and 51% of the company respectively.

On April 6th 2006 Microsoft Game studios purchased Lionhead Studios as they wanted to bolster the amount of releases for Xbox 360.In 2006 Microsoft also acquired Massive Inc, the in-game advertising company.