James Marbury "Sammy" Holbrook (July 17, 1910 - April 10, 1991) was an American Major League Baseball catcher. He played one season in the majors, in , for the Washington Senators. That year, he served as the primary backup to starting catcher Cliff Bolton.
Holbrook's minor league baseball career spanned 14 seasons, from until . In , he served as player-manager of the Federalsburg A's of the Eastern Shore League. Holbrook batted .361 in 98 games while leading the team to the league championship in his only season as manager.