William James Campbell (November 5, 1873 – October 6, 1957) was a professional baseball player. He was a left-handed pitcher over parts of four seasons (1905, 1907–09) with the St. Louis Cardinals and Cincinnati Reds. For his career, he compiled a 23–25 record, with a 2.80 earned run average, and 116 strikeouts in 407⅔ innings pitched. He was born in Pittsburgh, Pennsylvania and later died in Cincinnati, Ohio at the age of 83.