Léon Rosenfeld (14. 08.1904-5.04.1974) was a Belgian theoretical physicist. He was born in Charleroi (Belgium). He graduated from the University of Liège (1926), where he worked in 1930-40. In 1940 —47 he was professor at the University of Utrecht (Netherlands) and in 1947 — 58 at the University of Manchester (England). From 1958 he was professor at the Institute of Theoretical Nuclear Physics in Copenhagen.
His work concerned quantum electrodynamics, quantum mechanics, quantum field theory, nuclear physics, statistical mechanics and the history of physics. In 1928 he constructed a quantum theory of the optical activity of vapours, and in 1930 he made an attempt to quantise gravitation. In 1931, together with G. Wentzel, he laid the foundations of the general theory of quantised fields. He showed (1932) the equivalence of Dirac's mechanics and the Heisenberg — Pauli electrodynamics. In 1940 Rosenfeld and C. Møller postulated the existence of pseudoscalar and vector meson fields.
A member of a number of academies of sciences and learned societies.