Boatswain Müller is a fictional character in the story "The Temple" by H. P. Lovecraft. He served as a
boatswain aboard the German submarine U-29 under Lieutenant-Commander Karl Heinrich during the First World War.
Müller was an elderly man and described by Heinrich as a "superstitious Alsatian swine" (the region of Alsace, France
being under German control during the time period of the story).
During the supernatural events experienced by the crew, both Müller and Seaman Zimmer went missing. They were presumed by Heinrich to have committed suicide by jumping overboard while the U-29 was surfaced, victims of the fear that overcame them.