British chemist who did innovative research into conformational analysis (the study of the geometric structure of complex molecules), discovering that the reactivity of a molecule was related to its preferred shape. For this work he shared the 1969 Nobel Prize in Chemistry with Odd Hassel. One of Barton's many advances in organic chemistry was his use of free radicals, which enabled him to invent new reactions.

Barton was professor (1957–1970), Hofmann Professor (1970–1978) and then Emeritus Professor (1978–1998) of organic chemistry at Imperial College, London University. He was director (1977–1985) of the Institut de Chimie des Substances Naturelles (CNRS).