Delmer David Baker was an American professional baseball player, coach, and manager. During his time as a player, he spent three years (1914–1916) in Major League Baseball (MLB) as a backup catcher for the Detroit Tigers. As a manager, he led the 1940 Tigers to the American League pennant. He worked as a coach for 20 years for three American League teams, and was known as one of the premier sign stealers of his era. His professional career encompassed half a century in organized baseball.