Ralph Ward Stackpole (May 1, 1885 – December 13, 1973) was an American sculptor, painter, muralist, etcher and art educator, San Francisco's leading artist during the 1920s and 1930s. Born in Williams, Oregon, in Southern Oregon, Stackpole was involved in the art and causes of social realism, especially during the Great Depression, when he was part of the Federal Art Project for the Works Progress Administration (WPA). Stackpole was responsible for recommending that architect Timothy L. Pflueger bring leftist Mexican muralist Diego Rivera to San Francisco to work on the San Francisco Stock Exchange and its attached office tower in 1930 to 1931.