Riley M. Matheson (December 12, 1914 – June, 1987) was a professional American football player who played offensive lineman for ten seasons for the Cleveland / Los Angeles Rams, the Detroit Lions, and the San Francisco 49ers. Playing guard on offense and linebacker on defense, Matheson made both the Associated Press and United Press All-NFL Teams in 1944 and 1945. Matheson also played two final seasons with the Canadian Football League's Calgary Stampeders, being named an All star both seasons.