The famous philosopher who taught Alexander the Great was Aristotle. A prominent figure in ancient Greek philosophy, Aristotle was a student of Plato and later became the personal tutor to Alexander in his youth. Aristotle’s teachings encompassed a wide range of subjects, including philosophy, ethics, politics, science, and the arts. His influence helped shape Alexander’s approach to leadership and governance, emphasizing the importance of knowledge and rational thought. The philosophical groundwork laid by Aristotle played a crucial role in Alexander's later conquests, as well as in the Hellenistic culture that emerged following his empire's expansion.