Yajna or Yajñeśvara is mentioned as an avatar of the Hindu god Vishnu in Hindu literature. As Yajna, Vishnu is the embodiment of the Hindu sacrifice ritual, Yajna. He is also the Indra of the Svayambhuva Manvantara, the era of Svayambhuva Manu. His father is Ruci, and his mother is Ākūti.

Avatar is a concept within Hinduism that in Sanskrit literally means 'descent'. It signifies the material appearance or incarnation of a powerful deity, or spirit on Earth. The relative verb to "alight, to make one's appearance" is sometimes used to refer to any guru or revered human being.