Norris Edwin Bradbury, was an American physicist who served as Director of the Los Alamos National Laboratory for 25 years from 1945 to 1970. He succeeded Robert Oppenheimer, who personally chose Bradbury for the position of director after working closely with him on the Manhattan Project during World War II. Bradbury was in charge of the final assembly of "the Gadget", detonated in July 1945 for the Trinity test.

Bradbury took charge at Los Alamos at a difficult time. Staff were leaving in droves, living conditions were poor and there was a possibility that the laboratory would close. He managed to persuade enough staff to stay, and got the University of California to renew the contract to manage the laboratory. He pushed continued development of nuclear weapons, transforming them from laboratory devices to production models. Numerous improvements made them safer, more reliable and easier to store and handle, and made more efficient use of scarce fissionable materiel.

In the 1950s Bradbury oversaw the development of thermonuclear weapons, although a falling out with Edward Teller over the priority given to their development led to the creation of a rival nuclear weapons laboratory, theLawrence Livermore Laboratory. In later years, he branched out, constructing the Los Alamos Meson Physics Facility to develop the laboratory's role in nuclear science, and during the Space Race of the 1960s, the laboratory developed the Nuclear Engine for Rocket Vehicle Application (NERVA). The Bradbury Science Museum is named in his honor.