This is the first major study devoted to the early Arabic reception and adaption of the figure of Hermes Trismegistus, the legendary Egyptian sage to whom were ascribed numerous works on astrology, alchemy, talismans, medicine, and philosophy. The ancient Greek Hermetica, with which the tradition begins, are products of Roman Egypt of the second and third century CE. Thereafter, in late antiquity, they found a wide readership, both among pagans and Christians. Their ongoing popularity depended on the notion that Hermes had lived in extremely ancient times, perhaps before the Deluge, and his antiquity endowed him with a pristine intellectual priority and made him attractive as an authority in religious arguments. Early Arabic literature beginning in the eighth century also includes detailed discussions of Hermes Trismegistus, both as a teacher of ancient legend and as the alleged author of works on the apocryphal sciences, especially astrology. Moreover, Hermes is imagined in Arabic as a prophet, lawgiver, and the founder of ancient religion. This book shows how the Arabic Hermes developed out of the earlier Greek and other late antique traditions into something new, which would in turn form the background to the later reception of the Greek Hermetica in the Italian Renaissance. Assembling information in Greek, Arabic, Syriac, and Coptic primary sources, The Arabic Hermes will be of great interest to scholars in many fields, including Classics, Arabic Studies, Iranian Studies, Egyptology, and Medieval Studies.