Norman Foster Ramsey, Jr. (born August 27, 1915, in Washington, DC) is an American physicist. A physics professor at Harvard University since 1947, Ramsey also held several posts with such government and international agencies as NATO and the United States Atomic Energy Commission. He was awarded the 1989 Nobel Prize in Physics for the invention of the separated oscillatory field method, which had important applications in the construction of atomic clocks. Ramsey shared the prize with Hans G. Dehmelt and Wolfgang Paul.

Ramsey earned his B.A. and Ph.D. in physics from Columbia University in 1935 and 1940, respectively. He stayed on as a member of the Columbia faculty until 1947, when he moved to Harvard.