first human guru, or spiritual teacher, of the Nātha (Natha) cult, a popular Indian religious movement combining elements of Hinduism, Buddhism, and Haṭha Yoga, a form of yoga that stresses breath control and physical postures.

Matsyendranātha's name appears on both the lists of the 9 nāthas (“masters”) and the 84 mahāsiddhas (“great accomplished ones”) common to Hinduism and Buddhism. He was given semidivine status by his followers and identified with Avalokiteśvara-Padmapāni (a bodhisattva, or buddha-to-be) by his Buddhist followers in Nepal and with the god Śiva by his Hindu devotees. In Tibet he was known as Lui-pa. The name Mīna-nātha (“Fish-Lord”) refers, according to one legend, to his receipt of spiritual instruction from Śiva while in the form of a fish and in another legend to his rescue of a sacred text from the belly of a fish.

The historical details of Matsyendranātha's life are lost in the legends that have grown up around him. Though an ascetic he succumbed, according to one legend, to enchantments of two queens of Ceylon and had two sons, Pārosenāth and Nīmnāth, who were leaders of the Jaina religious sect. His leading disciple, Gorakhnāth (Gorakhnath), is commonly regarded as the founder of the Kānphaṭa Yogis, an order of religious ascetics who stress the practice of Haṭha Yoga.