Datsan (Mongolian: Дацан, Russian: Дацан) is the term used for Buddhist university monasteries in the Tibetan tradition of Gelukpa located throughout Mongolia, Tibet and Siberia. As a rule, in a datsan there are two departments—philosophical and medical. Sometimes to them is added the department of the tantric practices where the monks study only after finishing education in the philosophical department.
In pre-revolutionary Russia, datsans traditionally existed only in the Buryat territories, most of those now included in Buryatia and Transbaikalia (a number of datsans there has been reconstructed or started since the early 1990s). There was a difference with Tibetan administrative idea: in Tibet, several datsans were education-centered parts of larger organizations, as Drepung, Ganden, and Sera Monastery in Gelugpa tradition. In Russia, datsans were not parts of a larger entity, but rather independent educational and religious centers. In Buryat Buddhism, terms "Buddhist monastery" and "Datsan" are interchangeable, as other monastery organization forms found in Tibetan Buddhism elsewhere, were not present.
Datsans were officially acknowledged in Imperial Russia in 1734. By statute of 1853 there were two recognized datsans in the Irkutsk government and others in the Zabaykalsky Government. The first datsan in Europe was Datsan Gunzechoinei in St. Petersburg.