Metal Gear Solid 4: Guns of the Patriots[a] is a 2008 action-adventure game developed by Kojima Productions and published by Konami for the PlayStation 3 console. It is the sixth Metal Gear game directed by Hideo Kojima.

Set five years after the events of Metal Gear Solid 2: Sons of Liberty,the story centers around a prematurely aged Solid Snake, now known as Old Snake, as he goes on one last mission to assassinate his nemesis Liquid Snake, who now inhabits the body of his former henchman Revolver Ocelot under the guise of Liquid Ocelot, before he takes control of the Sons of the Patriots, an A.I. system that controls the activities of PMCs worldwide. It was released worldwide on June 12, 2008.

Guns of the Patriots received universal acclaim, garnering perfect reviews and Game of the Year awards from several major gaming publications, including GameSpot, which claimed that the game was "technically flawless". It is considered one of the seventh generation's console gaming's most significant titles and among the greatest video games ever made. Its release caused a boost in sales of the PlayStation 3, where it sold over six million copies worldwide.