According to the Buddhist Trikaya doctrine, Vairocana (also Vairochana or Mahavairocana; 大日如来 Chinese: Dàrì Rúlái, Japanese: Dainichi Nyorai) is a Buddha who is the embodiment of Dharmakaya, and which therefore can be seen as the universal aspect of the historical Gautama Buddha. In the conception of the Five Wisdom Buddhas, Vairocana is at the center.

Kaya means body. Trikaya means 'three bodies'. The Trikaya are: the Dharma Body or Dharmakaya, the Blissful Body, or Sambhogakaya, and the Reward Body, or the Nirmanakaya. Nirmana has almost the same meaning as the word avatar. Its meaning is akin to 'reflection', as the reflected moon in water. The Trikaya-theory is the expanded Mahayana teaching of somewhat later years. In the earliest Mahayana manuscripts, such as the Perfection of Wisdom (Prajnyaparamita) we only find two kaya: Buddha's Dharma Body and his Flesh and Blood body.

Vairocana is the central figure in the esoteric Shingon Buddhism in Japan, which is based largely on the teachings of the Mahavairocana Sutra . The Vairocana statue in Nara's Todaiji is the largest bronze image of Vairocana Buddha in the world. The larger of the monumental statues that were destroyed at Bamiyan in Afghanistan was a depiction of Vairocana.