Orphism is the name given to a set of religious beliefs and practices originating in Thrace and later spreading to the ancient Greek and Hellenistic world, associated with literature ascribed to the mythical Thracian poet Orpheus, who descended into the Greek underworld and returned. This type of journey is called a katabasis and is the basis of several hero worships and journeys. Orphics revered Dionysus and Persephone. Orphism has been described as a reform of the earlier Dionysian religion, involving a re-interpretation or re-reading of the myth of Dionysus and a re-ordering of Hesiod's Theogony, based in part on pre-Socratic philosophy.

The Derveni papyrus is an ancient Greek papyrus roll that was found in 1962. It is a philosophical treatise that is an allegorical commentary on an Orphic poem, a theogony concerning the birth of the gods, produced in the circle of the philosopher Anaxagoras. The roll dates to around 340 BC, during the reign of Philip II of Macedon, making it Europe's oldest surviving manuscript. The poem itself was composed near the end of the 5th century BC, and "in the fields of Greek religion, the sophistic movement, early philosophy, and the origins of literary criticism it is unquestionably the most important textual discovery of the 20th century." While interim editions and translations were published over the subsequent years, the manuscript as a whole was finally published in 2006.