David Leonard Chapman FRS (6 December 1869 – 17 January 1958) was an English physical chemist, whose name is associated with the Chapman-Jouguet treatment (on the theory of detonation in gases) and the Gouy-Chapman layer (the surface layer of ions distributed on a charged surface). He was a fellow of Jesus College, Oxford for 37 years, and was in charge there of the last college laboratory at the University of Oxford.