Gymnosophists (Ancient Greek: γυμνοσοφισταί, gymnosophistaí, i.e. "naked philosophers" or "naked wise men" (from Greek γυμνός gymnós "naked" and σοφία sophía "wisdom")) is the name given by the Greeks to certain ancient Indian philosophers who pursued asceticism to the point of regarding food and clothing as detrimental to purity of thought. They were noted to have been vegetarian by several Greek authors. There were also gymnosophists in Upper Egypt who were called Ethiopean Gymnosophists by Apollonius of Tyana.

In Greek literature, they are mentioned in association with the Persian magi, the Chaldaeans of the Assyrians or the Babylonians, the druids of the Celts, and the priests of Egypt. Some sources claim that famous figures such as Lycurgus, Pythagoras, and Democritus may have met them. They are mentioned by authors such as Philo, Lucian, Clement of Alexandria, Philostratus, and Heliodorus of Emesa. These reports are thought to have served as models to Cynics as well as Christian ascetics. Many authors have discussed the purported questions by Alexander the Great and answers by the Gymnosophists.