Zhu Xi (朱熹, Wade-Giles Chu Hsi, 1130 - 1200) in China was a Confucian and one of most significant Neo-Confucians. He taught at the famous White Deer Grotto Academy for some time. Considered unorthodox in their time, the Song Dynasty (960-1279), he and his fellow scholars added additional classic books: the Four Books, the Great Learning, and the Doctrine of Mean. Their writings were not widely recognised in Zhu Xi's time, however they subsequently became accepted as standard commentaries on the Confucian classics.

He was ranked the 45th Most Important Person in the last millennium by the Life magazine.