BioShock is a first-person shooter video game by 2K Boston/2K Australia—previously known as Irrational Games—designed by Ken Levine. The game is available for the Windows operating system and the Xbox 360 video game console. It was released on August 21, 2007, in North America, and three days later in Europe and Australia. On May 28, 2008, 2K Games confirmed that a PlayStation 3 version of the game is in development by 2K Marin, and will be released on October 21, 2008 in North America and October 24, 2008 internationally with some additional features. A version of the game for mobile platforms is currently being developed by IG Fun.

Set in an alternate history 1960, the game places the player in the role of a plane crash survivor named Jack, who must explore the underwater dystopian city of Rapture, and survive attacks by the mutated beings and mechanical drones that populate it. The game incorporates elements found in role-playing and survival horror games, and is described by the developers and Levine as a "spiritual successor" to their previous titles in the System Shock series.

The game received overwhelmingly positive reviews, and ranks as the thirteenth best video game on Game Rankings based on reviews from critics. It was particularly well-reviewed in the mainstream press where its "morality-based" storyline, immersive environment and Ayn Rand-inspired dystopic back-story were all singled out for praise. BioShock has been praised for providing "an entirely new tool through which to explore philosophy, psychology, and morality."