Infamous Second Son (stylized as inFAMOUS Second Son) is an open world, action-adventure video game developed by Sucker Punch Productions and published by Sony Computer Entertainment for the PlayStation 4. The game was released worldwide on March 21, 2014. Like in previous Infamous games, the player-controlled protagonist possesses superpower abilities that players use in combat. The story follows protagonist Delsin Rowe fighting the Department of Unified Protection (D.U.P.) in a fictionalized Seattle. Over the course of the game, Delsin acquires new powers and becomes either good or evil as player choices influence his morality.

Sucker Punch began planning the game as early as 2010, when they began discussion with Sony to bring the Infamous series onto a new generation of hardware. They provided feedback to Sony on what hardware evolutions they would like to see on the PlayStation 4 system. Second Son was considered a fresh start for the series because it features a new protagonist. Delsin Rowe's superpowers were designed to feel fluid and suited to the open world design.

Critical reviews were generally positive, with the gameplay, combat and visuals widely praised. However, the game was criticized on the morality system, which some reviewers found dated and binary, the protagonist and the game's repetitive side missions. The game sold over a million copies within nine days, making it the fastest-selling Infamous entry