John Stephen DeMerit (born January 8, 1936 in West Bend, Wisconsin) is an American former professional baseball player from Port Washington, Wisconsin. He was an outfielder over parts or all of five seasons (1957–1959; 1961–1962) with the Milwaukee Braves and New York Mets. Nicknamed "Thumper", DeMerit threw and batted right-handed and was listed as 6 feet 1 inch (1.85 m) tall and 195 pounds (88 kg). For his career, DeMerit hit .174 with 23 hits, three doubles, three home runs and seven runs batted in in 93 games played.