Tantra (/ˈtʌntrə, ˈtæn-/; Sanskrit: तन्त्र, literally “loom, weave, system”) denotes the esoteric traditions of Hinduism and Buddhism that co-developed most likely about the middle of the 1st millennium AD. The term tantra, in the Indian traditions, also means any investigative broadly applicable “text, theory, system, method, instrument, technique or practice”.

Starting in the early centuries of common era, newly revealed Tantras centering on Vishnu, Shiva or Shakti emerged. In Buddhism, the Vajrayana tradition is known for its extensive tantra ideas and practices. Tantric Hindu and Buddhist traditions have influenced extra Eastern religious traditions such as Jainism, the Tibetan Bön tradition, Daoism and the Japanese Shintō tradition.

Certain modes of non-worship such as Puja are considered tantric in their conception and rituals. Hindu temple building as a consequence generally conforms to the iconography of tantra. Hindu texts describing these topics are called Tantras, Āgamas or Samhitās. In Buddhism, its tantra-genre literature has influenced the artworks in Tibet, historic cave temples of India and imagery in Southeast Asia.