Rookes Evelyn Bell Crompton, CB, FRS (31 May 1845 – 15 February 1940) was a British electrical engineer, industrialist and inventor. He was a pioneer of electric lighting and public electricity supply systems. The company he formed, Crompton & Co., was one of the world's first large-scale manufactures of electrical equipment. He was also an early campaigner for an international standard for electrical systems. He was involved with both the practical and academic sides of his discipline, being a founder member of the International Electrotechnical Commission and twice president of the Institution of Electrical Engineers. He was a fellow of the Royal Society and a founder member of the Royal Automobile Club.