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, Kenneth J. Beattle, Robert Bee, R.D. Bookout, Crispin Burnham, R. S. Cartwright, Lee Clark, Jason Gridley, Peter F. Guenther, Jonathon William Hodges, Tani Jantsang, J.W. Kelley, D.F. Lewis, Philip Marsh, Andy Nunez, Brian Nutter, Duane Pesice, Robert M. Price, Joseph S. Pulver (Midnight Shambler), P.J. Roberts, Ron Shiflet, Kenneth Silver, G.W.Thomas and Peter A. Worthy.
Illustrations were done by T. Marsh.
Eighteen issues of Cthulhu Cultus appeared, the last one in 2001. The editors also recorded a 60 minute CD of original Cthulhu Cultus Music.