The mysterious protective seal of the Elder Gods of H.P. Lovecraft's mythos. Lovecraft's original design resembled a branch held diagonally, with three twigs extending from the upper side and two from the lower. August Derleth, an author who followed in Lovecraft's footsteps, apparently did not know of the pre-existing sigil when he created the more famous five-pointed star surrounding an eye, with a flame in place of the pupil.

The Elder Sign appears in several stories of the Cthulhu mythos and related stories, both by Lovecraft himself and others. Two known locations include Cthulhu's tomb in Rl'yeh and on one of the mountains in the dream-world. Exploration is not recommended.