Richard Earl Block (born 1931) is a mathematician at the University of California, Riverside who works on Lie algebras over fields of prime characteristic.
Block earned his Ph.D. from the University of Chicago in 1956. He was the first to discover the central extension of the Witt algebra that gives the Virasoro algebra, though his discovery went unnoticed for many years. With R. L. Wilson he classified the simple Lie algebras over "well behaved" fields of finite characteristic.
In 2012 he became a fellow of the American Mathematical Society.