Bacchus, in Roman religion and mythology, god of wine; in Greek mythology, Dionysus. Dionysus was also the god of tillage and law giving. He was worshiped at Delphi and at the spring festival, the Great Dionysia. In Rome, the mysteries of his cult were closely guarded, and he was identified with an ancient god of wine, Liber Pater. Many legends connected with Dionysus were also used in the cult of Bacchus.