Elkesai (also known as Elkasai, Elksai, Elchasai and Elxai) was a religious leader and prophet who is believed to have lived in the late 1st century CE and early 2nd century CE. He is primarily known through references in Christian, Manichaean, and other religious texts. Elkesai is associated with a religious movement known as the Elkesaites or Elkesaians, generally considered the founder of Elkesaism, which had significant influence on early Christian Gnostic and heterodox communities.