Robert Clayton Shantz (born September 26, 1925) is an American former professional baseball left-handed pitcher.

[1] He also played for the Pittsburgh Pirates, Houston Colt .45s, St. Louis Cardinals, Chicago Cubs, and the Philadelphia Phillies.

In a September 1952 game, Shantz's left wrist was broken after he was hit by a pitch thrown by Walt Masterson of the Senators.

On February 19, 1957, the Athletics traded Shantz, Art Ditmar, Wayne Belardi, Jack McMahan, and players to be named later (PTBNL) to the New York Yankees for Rip Coleman, Milt Graff, Billy Hunter, Mickey McDermott, Irv Noren, Tom Morgan, and a PTBNL.

[2] In the fifth and final inning of the 1952 All Star Game, the left–handed Shantz exhibited his distinctive sidearm delivery and sharp curve and control and struck out three consecutive National League hitters: Whitey Lockman, Jackie Robinson and Stan Musial.

Shantz appeared in relief three games each in the 1957 and 1960 World Series with the Casey Stengel managed New York Yankees.

[9] On June 15, 1964, the Cardinals traded Shantz, Ernie Broglio, and Doug Clemens to the Chicago Cubs for Lou Brock, Jack Spring, and Paul Toth.