Kratos is a character and the protagonist of Santa Monica Studio's God of War series, based on Greek mythology and, later, Norse mythology. He first appeared in the 2005 video game God of War, which led to the development of eight additional titles featuring the character as the protagonist. Kratos also appears as the protagonist of the 2010 and 2018 comic series, as well as three novels retelling the events of three of the games. The character was voiced by Terrence C. Carson from 2005 to 2013, with Christopher Judge taking over the role in 2018's continuation, also titled God of War. Antony Del Rio voiced a young Kratos in Ghost of Sparta.

In Greek mythology, Kratos, also known as Cratus or Cratos, is the divine personification of strength. He is the son of Pallas and Styx. Kratos and his siblings Nike ('Victory'), Bia ('Force'), and Zelus ('Glory') are all the personification of a specific trait. Kratos is first mentioned alongside his siblings in Hesiod's Theogony. According to Hesiod, Kratos and his siblings dwell with Zeus because their mother Styx came to him first to request a position in his regime, so he honored her and her children with exalted positions. Kratos and his sister Bia are best known for their appearance in the opening scene of Aeschylus' Prometheus Bound. Acting as agents of Zeus, they lead the captive Titan Prometheus on stage. Kratos compels the mild-mannered blacksmith god Hephaestus to chain Prometheus to a rock as punishment for his theft of fire.