Leonard Isaac Schiff (29.03.1915-1971) was an American theoretical physicist and a member of the National Academy of Sciences (1957). He graduated from Ohio University (1934) and the Massachusetts Institute of Technology (1937). In 1937-40 he worked at the California Institute of Technology, in 1940 — 47 at the University of Pennsylvania. From 1948 he was professor at Stanford University.
His work concerned nuclear physics, quantum mechanics, elementary particle physics, relativity and the theory of gravitation. He studied the scattering of high-energy electrons by charged extended particles and calculated the cross-section of the elastic scattering of an electron by a deuteron. Independently of others he built the betatron.