Stirling Auchincloss Colgate (/ˈkoʊlɡeɪt/; November 14, 1925 – December 1, 2013) was an American nuclear physicist at the Los Alamos National Laboratory and a professor emeritus of physics at the New Mexico Institute of Mining and Technology from 1965 to 1974, of which he also served its president.

After being discharged in 1946, Colgate returned to Cornell University, where he completed a Bachelor of Science in 1948 and a PhD in nuclear physics in 1951, then taking up a position as postdoctoral fellow at Berkeley.

His second job was measuring the range of energy of the neutrons and higher frequency gamma rays created by the nuclear tests.

In the 1950s Colgate was in charge of thousands during the Bravo test, the first deliverable thermonuclear bomb, which akin to his earlier work, included the atmospheric sampling Project Ashcan.

In 1956 Colgate and colleague Montgomery H. Johnson were recruited to investigate the resultant radiation and debris from a hydrogen bomb explosion in space.

In 1959, upon the advice of Los Alamos and Livermore National Laboratories, the State Department recruited Colgate as the scientific consultant on nuclear test ban negotiations in Geneva.

Some of these included DigAs (a search for early supernova in galaxies with a remote controlled telescope in real time using an IBM 360-44 mainframe computer through a digital microwave link from the New Mexico Tech campus to the school's Langmuir Laboratory) (see the PBS NOVA episode "Death of a Star", 1987, ca.

From 1975 until his death, Colgate worked at the Los Alamos National Laboratory (LANL) and was a professor emeritus at New Mexico Tech.

Colgate had a specially-designed laboratory on the New Mexico Tech campus where he continued his research until mid-2013, when he ceased work due to failing health.