Oberon Zell-Ravenheart (born Timothy Zell, November 30, 1942, St. Louis, Missouri; formerly known as Otter G'Zell) is a Neopagan writer, speaker and religious leader. He is the co-founder of the Church of All Worlds.
Zell took a Bachelor of Arts degree in psychology from Westminster College in Fulton, Missouri in 1965 before briefly enrolling in a doctoral program in clinical psychology at Washington University in St. Louis. He also received a Doctor of Divinity degree from Life Science College in Rolling Meadows, Illinois (a defunct nonresidential seminary analogous to the Universal Life Church) in 1967. In 1968, he completed a teaching certificate at Harris–Stowe State University.
In an interview with Natalie Zaman in 2008, Zell described himself as a wizard. Distinguishing his practice from the wizards of fiction, Zell used the alternative spelling magick (with final "k") and claimed that his interest therein began at an early age with the reading of Greek myths and fairy tales. As a child, Zell had visions, which his mother told him were derived from the life of his grandfather.
An early advocate of deep ecology, Zell-Ravenheart claims to have articulated the Gaia Thesis (using the spelling "Gaea") in 1970, independently of James Lovelock, who is usually given credit. Along with his wife Morning Glory and the other members of his group marriage, he has been influential in the modern polyamory movement.