Cthulhu Cultus was a fanzine published by Philip Marsh and Tani Jantsang. The Associate Editor was James Ambuehl.
Cthulhu Cultus was published in Florida, U.S.A. The first issue appeared in 1995. It was devoted to weird, supernatural and horror fiction and poetry with an emphasis on H. P. Lovecraft's Cthulhu Mythos.
Contributors included James Ambuehl, Robert Bee, R. S. Cartwright, Jason Gridley, Tani Jantsang, D.F. Lewis, Philip Marsh, Duane Pesice, Joseph S. Pulver, Ron Shiflet, and Peter A. Worthy.
Illustrations were done by T. Marsh.
Eighteen issues of Cthulhu Cultus appeared, the last one in 2001.