Leon James "Duke" Carmel (April 23, 1937 – August 3, 2021) was an American professional baseball player.

He had his MLB debut in September 1959, starting six games as the Cardinals' center fielder, but he collected only three hits and one base on balls in 24 plate appearances.

With regular play, his offensive performance perked up, and on August 8 at the Polo Grounds he had perhaps his best day as a major leaguer.

Playing against his old team, the Cardinals, Carmel went three for four, hitting his second career home run in the eighth inning, facing left-handed relief pitcher Bobby Shantz, to win the game, 3–2.

Selected by the Yankees in the Rule 5 draft, he began 1965 on the Bombers' roster, playing under his old St. Louis manager, Johnny Keane.