The smallest player to play in the major leagues was 3’7″ Eddie Gaedel. He made his only appearance on April 18, 1951 as part of a promotional stunt by the St. Louis Browns. Wearing the number 1/8, Gaedel was put in to pinch-hit for Frank Saucier in the bottom of the first. The opposing pitcher, Bob Cain, was unable to throw a pitch into Gaedel’s 1½-inch strike zone, and Gaedel walked on four pitches.
Gaedel was paid $100 dollars for his appearance. He was used in several other promotions over the years, but never played in another game.