A tulku (Tibetan: སྤྲུལ་སྐུ་, Wylie: sprul sku, ZWPY: Zhügu, also tülku, trulku) is an individual recognized as the reincarnation of a previous spiritual master (lama), and expected to be reincarnated, in turn, after death. The tulku is a distinctive and significant aspect of Tibetan Buddhism, embodying the concept of enlightened beings taking corporeal forms to continue the lineage of specific teachings. The term "tulku" is a loanword from Tibetan སྤྲུལ་སྐུ ("sprul sku"), which originally referred to an emperor or ruler taking human form on Earth, signifying a divine incarnation. Over time, it evolved within Tibetan Buddhism to denote the corporeal existence of certain highly accomplished Buddhist masters whose purpose was to ensure the preservation and transmission of a particular lineage.
The tulku system originated in Tibet, particularly associated with the recognition of the second Karmapa in the 13th century. Since then, numerous tulku lineages have been established, with each tulku having a distinctive role in preserving and propagating specific teachings. Other high-profile examples of tulkus include the Dalai Lamas, the Panchen Lamas, the Samding Dorje Phagmos, Khyentses, the Zhabdrung Rinpoches, and the Kongtruls.