William Vaness McGill (November 10, 1873 – August 29, 1944) was an American major league baseball pitcher.

He played professionally for the Cleveland Infants, Cincinnati Kelly's Killers, St. Louis Browns, Cincinnati Reds, Chicago Colts, St. Louis Browns and the Philadelphia Phillies.

McGill was born in Atlanta and attended the University of Notre Dame.

His best year was with the 1891 St. Louis Browns when he had a 19–10 record with a 2.93 ERA.

He finished his career with a 4.59 earned run average.