Erlik, or Erlik Khan ("King Erlik"), is a deity of the Turkic peoples of Siberia and of the Mongolian tribes. Generally, Erlik is considered to be lord of the lower world and judge of the dead.

It seems, however, that Erlik originally was a celestial god. This role can be surmised from Erlik's character as Lord Spirit of the Blue Boundlessness in the religion of the Yakuts of northeastern Siberia, who separated from their Turkic and Mongolian kinsmen in early times. Erlik's heavenly origin is also attested by Altai-Sayan Turkic tradition. Here, however, he has already been degraded to a position second to Ülgen, their supreme deity. He is the first man, Ülgen's brother or created by him, assisting him in the creation of the earth. Erlik wants to become equal to Ülgen, however; he wants to create land himself. He also tries to seize all human beings created by Ülgen, seducing them to take forbidden food from the first tree. As a result, Erlik is banished from the celestial realm.