William Joseph Haselman (born May 25, 1966) is an American professional baseball coach and former player. He played as a catcher in Major League Baseball (MLB) for 13 seasons between 1990 and 2003. A first-round selection in the 1987 MLB draft, he played for the Texas Rangers, Seattle Mariners, Boston Red Sox and Detroit Tigers. He later was the bullpen coach and first base coach for the Red Sox, and currently is the third base and catching coach for the Los Angeles Angels. He has also served as a manager in the minor leagues.