Elmer William Colglazier (born November 24, 1944) is an American physicist, best known as the fourth science and technology adviser to the U.S. Secretary of State.

While at Harvard, he also served as associate director of the Program in Science, Technology, and Humanism of the Aspen Institute.

[2] From 1983 to 1991, he was professor of physics and director of the Energy, Environment, and Resources Center at the University of Tennessee, where he worked closely with scientists at Oak Ridge National Laboratory.

They have two married children: Geraldine Tunnell, Senior VP for Marketing at Dell, and Will Colglazier, US History teacher at Aragon High School (CA).

He resides in McLean, VA.[citation needed] This article incorporates public domain material from websites or documents of the Department of State.