William Henry Abstein (February 2, 1883 – April 8, 1940), nicknamed "Big Bill", was a professional baseball and amateur soccer player. He played all or part of three seasons in Major League Baseball player, from 1906 to 1910, primarily as a first baseman. He played for the Pittsburgh Pirates and St. Louis Browns. He played in 170 games, with 150 hits, one home run, 76 RBI and a batting average of .242. He played for Pittsburgh during the 1909 World Series, appearing in all seven games and getting six hits.