George M. "Potsy" Clark (March 20, 1894 – November 8, 1972) was an American football and baseball player, coach, and athletics administrator. He served as the head football coach at Michigan Agricultural College, now Michigan State University, (1920), the University of Kansas (1921–1925), Butler University (1927–1929), and the University of Nebraska–Lincoln (1945, 1948), compiling a career college football record of 40–45–7. Clark was also the head coach of the National Football League's Portsmouth Spartans/Detroit Lions (1931–1936, 1940) and Brooklyn Dodgers (1937–1938), amassing a career NFL mark of 64–42–12. Clark's 1935 Detroit Lions team won the NFL Championship. From 1945 to 1953, Clark served as the athletic director at Nebraska.

As a member of the American Expeditionary Force (AEF) during World War I, Clark was a member of the U.S. Army's 89th Division's football team that won the AEF championship in March 1919. In a team with many college football stars, Charles Gerhardt played quarterback and Clark played left halfback under the direction of right guard, team captain and coach Paul Withington.