Longchen Rabjam Drimé Özer, commonly abbreviated to Longchenpa was a Tibetan scholar-yogi of the Nyingma school of Tibetan Buddhism. According to tibetologist David Germano, Longchenpa's work led to the dominance of the Longchen Nyingthig lineage of Dzogchen over the other Dzogchen traditions. He is also responsible for the scholastic systematization of Dzogchen thought within the context of the wider Tibetan Vajrayana tradition of philosophy which was highly developed at the time among the Sarma schools. Germano also notes that Longchenpa's work is "generally taken to be the definitive expression of the Great Perfection with its precise terminological distinctions, systematic scope, and integration with the normative Buddhist scholasticism that became dominant in Tibet during the thirteenth and fourteenth centuries."

Nyingma, often referred to as Ngangyur, is the oldest of the four major schools of Tibetan Buddhism. The Nyingma school is founded on the first lineages and translations of Buddhist scriptures from Sanskrit into Tibetan in the eighth century, during the reign of King Trisong Detsen.