member of a Jewish sect that arose in the vicinity of Trans-Jordanic Palestine around 100 AD. The sect was most noted for its practice of ritual baptism. Named after either a visionary leader named Elkesai or the book of revelation that bore his name, the group followed most Jewish laws, believed in the power of total-immersion baptism to remit sins, and may have practiced a form of communion with bread and salt.

Elkesaism drew followers from the Essene sect of Judaism and from among the Aramaic Jewish-Christians in the region of the Dead Sea. In later years, by 220 AD, the group adopted a Christological doctrine, apparently in an attempt to attract Greek-speaking Christians, but had virtually died out by 400 AD.