Frederick Seitz (born 4. VII 1911) was an American physicist, a member of the National Academy of Sciences (1951) and its president in 1962—69. He was born in San Francisco. He graduated from Stanford University (1932). In 1935 — 37 he worked at the University of Rochester, in 1937 — 39 at the General Electric Company and in 1939—41 at the University of Pennsylvania; in 1942 — 49 he was professor at the Carnegie Institute of Technology and in 1949—64 at the University of Illinois. In 1968 — 78 he was president of Rockefeller University.
His work concerned solid-state physics, in particular the theory of metals, and nuclear physics. He formulated the symmetry principles of crystals in matrix form. He proposed one of the methods of quantitative assessment of the behaviour of electrons in a real metal (the cellular method).
In 1961 he was president of the American Physical Society. The B. Franklin Medal (1965). The National Medal of Science (1973).