Epimenides of Crete was a semi-legendary seer and purifier active in the late 7th or 6th century BCE. Ancient sources report that he purified Athens of a religious pollution following the Cylonian affair, employing novel rites. His life is heavily mythologized, including tales that he slept in a cave for decades, awakening with prophetic powers, and that he lived an extraordinarily long life. He is often grouped with other archaic mystic figures and was sometimes counted among the Seven Sages.

All works attributed to Epimenides are lost and considered spurious. Ancient testimony credits him with several theological and theogonic writings in prose, such as a Theogony, On Sacrifices and the Cretan Constitution, and On Minos and Rhadamanthys. He was also credited with oracular verses, most famously the line quoted in the New Testament: "Cretans are always liars, evil beasts, lazy gluttons."

Epimenides represents the pre-philosophical wandering religious expert in Greek tradition. His legendary purification was a foundational story for Athenian civic religion. He is remembered in logic for the "Cretan liar" statement, a classical antecedent to the Liar Paradox.