As a genre, “apocalypse” is of enormous importance for understanding Gnosticism. However, the Gnostic apocalypses have often been approached by modern scholars in terms of the relationship between “apocalypticism” and “Gnosticism.” Scholarship has now turned away from the study of “apocalypticism” and towards the texts themselves, the apocalypses. This chapter examines the Gnostic apocalypses—that is, apocalyptic literature that addresses the Gnostic myth and uses the genre “apocalypse”—and compares them with their Jewish and Christian counterparts. It begins with a discussion of the First Apocalypse of James and Zostrianos before turning to the views of Valentinian Gnostics about apocalypse. It then considers how the authors of the Gnostic apocalypses approached myth, allegory, and authority in ways that differ considerably from Hellenic philosophy. It also looks at the reception of Jewish apocalypses, Gnostic myths, and Hellenic, philosophical allegory in the birth of Manichaeism. It concludes with the argument that Gnostic apocalypses are the ultimate affirmation of revelatory authority