William Calvin Matthews (January 5, 1877 – January 23, 1946) was an American baseball player. He was a right-handed pitcher in Major League Baseball who played briefly for the Boston Red Sox during the 1909 season. He was born in Mahanoy City, Pennsylvania.
Matthews posted a 3.24 ERA in five appearances, including one start, six strikeout, 10 walks, 16 hits allowed, and 16.2 innings of work. He did not have a decision.
Matthews died in Mount Carbon, Pennsylvania, at age 68.