The Esoteric Order of Dagon is a fictional cult in Innsmouth from Howard Phillips Lovecraft's The Shadow Over Innsmouth.

Captain Obed Marsh founded the cult using the practices learned from the inhabitants of a Polynesian island. The people of Innsmouth carried out ritual sacrifices on Devil's Reef to appease the Deep Ones. In 1846 during one of these sacrifices Captain Marsh and several members of the Order of Dagon were arrested, though no formal charges were made. It was disbanded when the U.S. goverment launched an attack on the town in 1928.