Sextus Empiricus (Greek: Σέξτος Ἐμπειρικός; c. 160 – c. 210 AD, n.b., dates uncertain), was a physician and philosopher, and has been variously reported to have lived in Alexandria, Rome, or Athens. His philosophical work is the most complete surviving account of ancient Greek and Roman Pyrrhonism.

In his medical work, as reflected by his name, tradition maintains that he belonged to the empiric school, in which Pyrrhonism was popular. However, at least twice in his writings, Sextus seems to place himself closer to the methodic school. He may be the same person as Sextus of Chaeronea.