Thomas Keith Glennan (September 8, 1905 - April 11, 1995) was the first Administrator of the National Aeronautics and Space Administration, serving from August 19, 1958 to January 20, 1961.
As NASA Administrator, Glennan presided over an organization that had absorbed the earlier National Advisory Committee for Aeronautics (NACA) intact; its 8,000 employees, an annual budget of US$100 million, and three major research laboratories—Langley Aeronautical Laboratory, Ames Aeronautical Laboratory, and Lewis Flight Propulsion Laboratory—and two small test facilities made up the core of the new NASA.
Within a short time after NASA's formal organization, Glennan incorporated several organizations involved in space exploration projects from other federal agencies into NASA to ensure that a viable scientific program of space exploration could be reasonably conducted over the long-term. He brought in part of the Naval Research Laboratory in NASA and created for its use the Goddard Space Flight Center.