John Costen Shockley (born February 8, 1942 in Georgetown, Delaware) is an American retired professional baseball player who appeared in 51 Major League games for the Philadelphia Phillies (1964) and Los Angeles Angels (1965). A first baseman who batted and threw left-handed, Shockley was listed as 6 feet 2 inches (1.88 m) tall and 200 pounds (91 kg). His 28 career big-league hits included two doubles and three home runs. He collected 19 runs batted in.