Zhu Xi ( October 18, 1130 – April 23, 1200) is a Song dynasty Confucian scholar who is the leading figure of the School of Principle and the most influential rationalist Neo-Confucian in China.

His contributions to Chinese philosophy including his assigning special significance to the Analects, the Mencius, the Great Learning, and the Doctrine of the Mean (the Four Books), his emphasis on the investigation of things (gewu), and the synthesis of all fundamental Confucian concepts, form the basis of Chinese bureaucracy and government for over seven hundred years.

He has been called the second most influential thinker in Chinese history, after Confucius himself.