BioShock Infinite is a first-person shooter video game developed by Irrational Games and published by 2K. The third installment of the BioShock series, Infinite was released worldwide for the PlayStation 3, Windows, Xbox 360, and OS X platforms in 2013. The game is set in the year 1912 and follows its protagonist, Booker DeWitt, who is sent to the airborne city Columbia to retrieve Elizabeth, a young woman held captive there. Booker and Elizabeth become involved in a class war between the nativist Founders that rule Columbia and the rebel Vox Populi, representing the city's underclass. Elizabeth possesses the ability to manipulate "Tears" in the space-time continuum, and Booker and Elizabeth discover she is central to Columbia's dark secrets. The player controls Booker DeWitt throughout the game, fighting enemies and scavenging supplies, while the computer-controlled Elizabeth provides assistance.

After the 2007 release of BioShock, Irrational Games and creative director Ken Levine were initially uninterested in creating a sequel, but they later renegotiated with 2K to produce another BioShock game. Irrational based the game's setting on historical events at the turn of the 20th century, such as the 1893 World's Columbian Exposition, and based the story on the concept of American exceptionalism while also incorporating influences from more recent events at the time such as the 2011 Occupy movement. The relationship between Booker and Elizabeth became central to the story, with the team working to make Elizabeth feel like a real character rather than a computer-controlled sidekick.

The game's development took five years and involved hundreds of employees at Irrational, in addition to support studios. The development process was troubled, with Levine's management style resulting in wasted work and missed deadlines. Outside help was brought in to make sure the game shipped. BioShock Infinite was supported post-launch with downloadable content, including the story expansion Burial at Sea, which links Infinite's story to that of the original BioShock game.

BioShock Infinite received critical acclaim, with praise particularly directed at its story, setting, visual design, and art direction. It has sold more than 11 million copies worldwide. Infinite was released on PlayStation 4, Xbox One, and Nintendo Switch as part of BioShock: The Collection.

BioShock Infinite is set in 1912 and takes place in a floating steampunk city-state in the sky called "Columbia", named for the female personification of the United States. The city of Columbia was founded by self-proclaimed prophet Zachary Hale Comstock, and funded by the United States government as a floating world's fair and display of American exceptionalism. Tensions rose between Columbia and the government after the city independently intervened in the Boxer Rebellion, and Columbia ultimately seceded from the United States and disappeared into the clouds. Comstock transforms the city into a theocratic police state, with Comstock worshipped as a prophet, and the Founding Fathers of the United States venerated as religious icons. Institutional racism and elitism are widespread in the city, with minorities serving as a labor underclass of Columbia. By the events of the game, Columbia is on the verge of civil war; the Founders of Columbia are opposed by the Vox Populi, a resistance group led by Daisy Fitzroy who fight for the rights of the marginalized.

Columbia is home to "Tears" in the fabric of space-time. These Tears reveal alternate universes. Some individuals exploit the insight offered by the tears to create new weapons and technologies, while several others replicate futuristic media heard from the Tears, bringing anachronistic elements into Columbia.

The player controls protagonist Booker DeWitt, a U.S. Army veteran and disgraced member of the Pinkerton National Detective Agency scarred from a life of violence. Faced with mounting gambling debts, he is sent to Columbia to find a young woman, Elizabeth, who has the ability to open Tears. Confined in isolation in Columbia since childhood, Elizabeth has been groomed as the city's future leader and is guarded by Songbird, a large, robotic bird-like creature who has served as both her friend and warden. Two individuals, Robert and Rosalind Lutece, direct Booker to Columbia and appear throughout his travels. Though they appear as twins, they are revealed to be the same person from two different realities, having figured out how to communicate through and subsequently cross realities.

In July 1912, Booker DeWitt arrives in Columbia, where he is soon pursued by authorities who recognize him as a "False Shepherd" who is prophesied to attempt to corrupt Elizabeth and overthrow Columbia. Freeing Elizabeth from her tower, Booker narrowly evades Songbird. Commandeering an airship, Booker lies that he will take Elizabeth to Paris; when she realizes they are going to New York City to fulfill Booker's debts, Elizabeth knocks him unconscious and flees. Booker awakens to find the airship commandeered by Daisy Fitzroy, who offers to return the ship if Booker helps her arm the Vox Populi.