Clifford Charles Butler (born 20.05.1922) is an English physicist and a Fellow of the Royal Society (from 1961). He was born in Reading, where he graduated from the university (1942). In 1945—53 he worked at the University of Manchester and in 1953—70 at the University of London (from 1957 as professor). In 1970—75 he was director of the Nuffield Foundation, and from 1975 vice-chancellor of Loughborough University of Technology.
His work was in the field of atomic and nuclear physics and the physics of cosmic rays and elementary particles. In 1947, together with G. Rochester, he discovered the first strange particles, the charged and neutral K-mesons and the hyperons. He took part in the discovery of the lambda-zero hyperon (1951) and the xi-minus hyperon (1952).
In 1975—78 he was president of the International Union of Pure and Applied Physics.