An ancient bishop of the Christian church, from Kashkar, in Mesopotamia. It should be noted, however, that there is some dispute over his place of origin, too long to relate in depth here. His feast day is December 26.

St. Archelaus is most well known for his Disputation with Mani - Manes in the Latin - founder of Manicheism, which occurred in 277 AD. He is thus best known for fighting the Manicheist heresy of the time.