Nisargadatta Maharaj (17 April 1897 – 8 September 1981) was an Indian Guru of nondualism, belonging to the Inchagiri Sampradaya, a lineage of teachers from the Navnath Sampradaya and Lingayat Shaivism. The publication in 1973 of "I Am That" talks with Sri Nisargadatta Maharaj, an English translation of his talks in Marathi by Maurice Frydman, brought him worldwide recognition and followers, especially from North America and Europe. 

Nisargadatta's teachings are grounded in the Advaita Vedanta interpretation of the Advaita idea Tat Tvam Asi, literally "That Thou Art", (Tat = "Absolute", Tvam = "You", Asi = "are") meaning "You are (actually) Absolute" (who think otherwise). Nisargadatta also had a strong devotion to his own guru, and suggested the path of devotion, Bhakti yoga, to some of his visitors. Nisargadatta deviated from the formal Navnath Sampradaya lineage style of teaching by giving informal discourses for the benefit of Western devotees who did not have access to Dasbodh or other texts, and who were not familiar with Indian traditions and customs. It has been said that Nisargadatta´s style was direct, and even at times aggressive. He very rarely mentioned scriptures or quoted spiritual books. His teachings came from his own experience

Sri Nisargadatta Maharaj gave mantra initiation, with the underlying point being that the mantra was more than sound, it was the Absolute Itself which could be reverberated throughout life in all circumstance.