David Mathias Dennison (26.04.1900 —3.04.1976) was an American theoretical physicist and a member of the National Academy of Sciences (1953). He was born in Oberlin. In 1924 he received the degree of Doctor of Philosophy at the University of Michigan, where he worked in 1927-70 (professor from 1935).
His research concerned the study of molecular structure, atomic and nuclear physics, infrared spectroscopy and the physics of accelerators. In 1927 he postulated that the proton has a spin and obtained the value 1/2H for its magnitude. Together with G. Uhlenbeck he determined (1932) the structural configuration of the ammonia molecule.