William Henry Walker (October 7, 1903 – June 14, 1966) was an American professional baseball left-handed pitcher over parts of ten seasons (1927–1936) with the New York Giants and St. Louis Cardinals. He was the National League ERA champion twice (1929 and 1931) with New York. For his career, Walker compiled a 97–77 record in 272 appearances with a 3.59 ERA and 626 strikeouts.
Walker was born and later died in East St. Louis, Illinois, on June 14, 1966, at the age of 62. He is buried in Belleville, Illinois.