William Joseph "Jap" Barbeau (June 10, 1882 – September 10, 1969) was an American professional baseball infielder. He played in Major League Baseball for four seasons, primarily as a third baseman with the Cleveland Naps, Pittsburgh Pirates, and St. Louis Cardinals. Listed at 5 feet 5 inches (1.65 m) and 140 pounds (64 kg), he batted and threw right-handed.