Dennis Michael Riddleberger (born November 22, 1945) is an American former Major League Baseball pitcher. Listed at 6 feet 3 inches (1.91 m), 195 pounds (88 kg), Riddleberger threw left-handed and batted right-handed. Riddleberger spent the entire 1971 season in the majors, but after getting off to a slow start (11.12 ERA in April), found himself doing mostly mop-up duty. The Senators were 14-43 in games in which Rittleberger pitched. He ended the season with a 3-1 record and a far more respectable 3.23 ERA. He earned his only career save on July 5 against the Cleveland Indians.