Jupiter, in Roman religion and mythology, the supreme god, also called Jove. Originally a sky deity associated with rain and agriculture, he developed into the great father god, prime protector of the state, concerned, like the Greek Zeus (with whom he is identified), with all aspects of life. At his temple on the Capitol, triumphant generals honored him with their spoils and magistrates paid homage to him with sacrifices. Jupiter was the son of Saturn and Ops and the brother and husband of Juno.