Clarence McKay "Ace" Parker (May 17, 1912 – November 6, 2013) was an American football and baseball player and coach. He played professional football as a quarterback in the National Football League (NFL) for the Brooklyn Dodgers (1937–1941) and Boston Yanks (1945) and in the All-America Football Conference (AAFC) for the New York Yankees. He was an All-American halfback at Duke University in 1936. Parker also played Major League Baseball during 1936 and 1937 with the Philadelphia Athletics. He served as the head baseball coach at Duke from 1953 to 1966. Parker was inducted into the College Football Hall of Fame in 1955 and the Pro Football Hall of Fame in 1972.