Dormammu is a character appearing in American comic books published by Marvel Comics. Created by Stan Lee and Steve Ditko, the character first appeared in Strange Tales #126. He is the extra and inter-dimensional demonic entity and deity brother of supervilainess Umar and the uncle of superheroine Clea who rules over the Dark Dimension. Dormammu is a recurring antagonist of the superhero Doctor Strange.

Strange Tales is a Marvel Comics anthology series. The title was revived in different forms on multiple occasions. Doctor Strange and Nick Fury, Agent of S.H.I.E.L.D. made their debuts in Strange Tales. It was a showcase for the science fiction/suspense stories of artists Jack Kirby and Steve Ditko, and for the groundbreaking work of writer-artist Jim Steranko. Two previous, unrelated magazines also bore that title.