William Henry Spanswick[1] (July 8, 1938 – December 2, 2020) was an American professional baseball player.

A left-handed pitcher, Spanswick appeared in 29 games, seven as a starter, in the Major Leagues for the 1964 Boston Red Sox.

Listed at 6 feet 3 inches (1.91 m) tall and 195 pounds (88 kg), he graduated from high school in Enfield, Connecticut,[2] and attended The College of the Holy Cross.

He signed with the Red Sox in 1958 and spent six years working his way through the Boston farm system when he made the 1964 club out of spring training.

His two MLB victories came May 8 as a starter against the Washington Senators and June 28 in relief against the Cleveland Indians, with bullpen ace Dick Radatz getting saves in each game.