Harry Glicken (March 7, 1958 – June 3, 1991)[1] was an American volcanologist. He researched Mount St. Helens in the United States before and after its 1980 eruption, and was very distraught about the death of volcanologist David A. Johnston, who was Glicken's mentor and supervisor in Spring 1980 at Mount St. Helens. Glicken was initially assigned to the USGS observation post in the weeks leading up to the eruption but was called away the night before the eruption.