Killzone is a series of first-person shooter video games for Sony Interactive Entertainment's (SIE) video game consoles. The main series and the PlayStation Portable (PSP) installment were developed by Guerrilla Games, a subsidiary of SIE, and the PlayStation Vita installment was developed by Guerrilla Cambridge. Killzone consists of six games, beginning on the PlayStation 2 in November 2004 with Killzone, and continued on the PlayStation Portable in October 2006 with Killzone: Liberation. Killzone 2 was released for the PlayStation 3 in February 2009, and Killzone 3 was released in February 2011, also for the PlayStation 3. Killzone: Mercenary was released for the PlayStation Vita in September 2013, followed by Killzone: Shadow Fall, a launch title for the PlayStation 4, in November 2013.

Sony Interactive Entertainment LLC (SIE) is an American multinational video game and digital entertainment company of Sony. Jointly established by two subsidiaries in 2016, it primarily operates the PlayStation brand of video game consoles and products. It is also the world's largest company in the video game industry based on its equity investments.