Pherecydes of Syros (born c. 550 bce) was a Greek mythographer and cosmogonist traditionally associated with the Seven Wise Men of Greece (especially Thales).
Pherecydes is credited with originating metempsychosis, a doctrine that holds the human soul to be immortal, passing into another body, either human or animal, after death. He is also known as the author of Heptamychos, a work, extant in fragments only, describing the origin of the world from a divine trinity: Zas (Zeus), Chronos or Kronos, and Chthonie or Ge (Mother Earth). Pherecydes was characterized by Aristotle in Metaphysics, Book XIV, as a theologian who mixed philosophy and myth. Tradition says that he was the teacher of Pythagoras. He is not to be confused with Pherecydes of Athens, a genealogist who lived about a century later.