In Tibetan Buddhism, a tulku (Tibetan: སྤྲུལ་སྐུ, Wylie: sprul sku, ZYPY: Zhügu, also tülku, trulku) is a particular high-ranking lama (e.g., the Dalai Lama, the Panchen Lama, the Karmapa) who can choose the manner of his (or her) rebirth. Normally the lama would be reincarnated as a human, and of the same sex as his (or her) predecessor. In contrast to a tulku, all other sentient beings including other lamas, have no choice as to the manner of their rebirth.^{[clarification needed]} In addition to choosing the manner of their rebirth, tulkus are able, on their deathbed, to make known the place of their next birth.

It has been estimated that there are presently about 500 tulkus found across Tibet, although before the Chinese invasion there were probably a few thousand. Each tulku has a distinct lineage of rebirths. For example, the Fourteenth Dalai Lama is held to be the reincarnation of each of the previous thirteen Dalai Lamas of Tibet, who are in turn considered to be manifestations of Avalokiteshvara, or Chenrezig, Bodhisattva of Compassion, holder of the White Lotus. The vast majority of tulkus (and lamas) are men, although some are women.