William Madison Lewis Sr. (26 November 1921 in Faison, North Carolina – 15 May 2010 in Clinton, North Carolina) was a fish biologist who founded the Fisheries and Illinois Aquaculture Center at Southern Illinois University Carbondale. He attended Iowa State University where he obtained M.A. and Ph.D. degrees in zoology specializing in fisheries science. In 1950 he became a professor at Southern Illinois University, where he founded and directed the Southern Illinois University Carbondale Cooperative Fisheries Research Program, now called the Fisheries and Illinois Aquaculture Center. His mission for the program was to study the fishes of Illinois and to train graduate students in fisheries science and aquaculture.