The story of the Athenian Tyrannicides Harmodios and Aristogeiton is well known to modern scholars who agree that the two men were figures of cult. The occasion for these rituals has inspired rather less agreement and the rites have often been connected with the Epitaphia. In this article, I re-examine the ritual setting of the cult. As I argue, evidence not previously brought into these discussions identifies the Panathenaia as the primary occasion for the Tyrannicides' rituals. This connection is further reinforced by other visual imagery (Panathenaic amphorae, sculpture, vase-painting) which links Harmodios and Aristogeiton to the festival of Athena and its celebration of divine victory over the Giants.