Tengrism, also known as Tengriism or Tengrianism, is a Central Asian religion characterized by shamanism, animism, totemism, poly- and monotheism and ancestor worship. It was the prevailing religion of the Turks, Mongols, Hungarians, Xiongnu and Huns, and the religion of the five ancient Turkic states: Göktürk Khaganate, Western Turkic Khaganate, Great Bulgaria, Bulgarian Empire and Eastern Tourkia (Khazaria). In Irk Bitig, Tengri is mentioned as Türük Tängrisi (God of Turks).
Tengrism has been advocated in intellectual circles of the Turkic nations of Central Asia (including Tatarstan, Buryatia, Kyrgyzstan and Kazakhstan) since the dissolution of the Soviet Union during the 1990s. Still practiced, it is undergoing an organized revival in Sakha, Khakassia, Tuva and other Turkic nations in Siberia. Burkhanism, a movement similar to Tengrism, is concentrated in Altay.