William Lavier Killefer (October 10, 1887 – July 3, 1960), nicknamed "Reindeer Bill" was an American professional baseball player, coach and manager. He played in Major League Baseball as a catcher for the St. Louis Browns, Philadelphia Phillies, and Chicago Cubs. Killefer, who was nicknamed "Reindeer Bill" due to his speed afoot, is notable for being the favorite catcher of Hall of Fame pitcher Grover Cleveland Alexander and, for being one of the top defensive catchers of his era. After his playing career, he continued to work as a coach and a manager for a Major League Baseball career that spanned a total of 48 years.