Kenneth Leo Retzer (born April 30, 1934 in Wood River, Illinois) is a former Major League Baseball catcher. He was signed by the Cleveland Indians before the 1954 season, but played his entire MLB career for the Washington Senators (1961-1964).
Retzer played semi-regularly for Washington in 1962 and 1963, starting 91 and 72 games, respectively. He was a defensive catcher with a lifetime fielding percentage of .983. He threw out 48 of 126 baserunners making stolen base attempts, which is 38.1%.
He finished his career with a lifetime batting average of .264, 14 home runs, 72 runs batted in, and 65 runs scored in 237 ballgames. He caught the first pitch of the 100,000 MLB game. The ball caught was presented to and placed in the Baseball Hall of Fame. He also caught President John F. Kennedy's first day game throw out pitch.