Audianism was a Fourth Century Christian heresy.

The Audians were named after their leader, Audius (or Audaeus). Their heretical beliefs included both anthropomorphism (holding that God has human form) and quartodecimanism (honouring the death of Christ on the same day as the Jewish Passover).

The First Council of Nicaea, which attempted to unify the early church, finally outlawed quartodecimanism. The Audians, however, continued this practice. Epiphanius called attention to the Audian heresy (as well as other heresies) in his Panarion. He wrote of the Audians' claim that the church had "abandoned the fathers' Paschal rite in Constantine's time from deference to the emperor, and changed the day to suit the emperor" (Panarion, Book III, Haer.70, Chap.9). Emperors Constantine the Great and Theodosius I legislated against the Audians, but the sect was still practicing quartodecimanism in Syrian Antioch in the 380s.