Cecil Edgar Tilley (born May 14, 1894, Adelaide, Australia—died Jan. 24, 1973, Cambridge, Cambridgeshire, Eng.) was a British mineralogist known for his investigations of mineral and rock synthesis. Tilley became a professor at Cambridge University in 1931, retiring in 1961 as professor emeritus. Tilley’s work also includes studies of tektites (glassy objects of meteoric origin) and their comparison to volcanic glasses.