Acharya N?g?rjuna (Devanagri:?????????, Telugu (Telugu script): ?????????, Tibetan (Standard Tibetan): ?????????? klu sgrub, Chinese (Chinese language): ??) (c. 150 - 250 CE (Common Era)) was an Indian philosopher (Indian philosophy) who founded the Madhyamaka school of Mah?y?na Buddhism Citation neededdate=May 2010.

His writings are the basis for the formation of the Madhyamaka school, which was transmitted to China under the name of the Three Treatise (Sanlun) School. He is credited with developing the philosophy of the Prajnaparamita sutras, and was closely associated with the Buddhist university of Nalanda. In the Jodo Shinshu branch of Buddhism, he is considered the First Patriarch (Jodo Shinshu Patriarchs).

Little is known about the actual life of the historical Nagarjuna. The two most extensive biographies of Nagarjuna, one in Chinese and the other in Tibetan, were written many centuries after his life and incorporate material seen by some as historically unreliable. Nagarjuna was born a Brahmin, which in his time connoted religious allegiance to the Vedas, probably into an upper-caste Brahmin family and probably in the southern Andhra region of India.