Namkhai Nyingpo (8th/9th century CE) (Wylie: gNubs Nam-mkha'i sNying-po) is counted amongst the principal 'twenty-five disciples' of Padmasambhava.

Namkhai Nyingpo was a realized practitioner of Shantarakshita's tradition of Sutrayana and 'gradual' Mahayana; as well as simultaneously being one of the most accomplished Tibetan practitioners of the Chinese Ch'an School (East Mountain Teachings); which transmits the T鰊mun or 'sudden' tradition of the Mahayana.

In addition; Namkhai Nyingpo was also a realized master of the Dzogchen path (Atiyogayana) of 'self-liberation' (Wylie: rang grol); as well as a Master of the Tantric Path (Tantrayana) of transformation (specifically; the three Outer Tantra yana and the Inner Tantra yana bar Dzogchen according to the scheme of the Nyingmapa).

'Namkhai Nyingpo' (Tibetan; Sanskrit: Akasagarbha) may be rendered in English from the Tibetan as 'essence of space' or 'matrix of the sky'.