Billy Mike Smithson (born January 21, 1955) is an American former Major League Baseball (MLB) right-handed pitcher who played for the Texas Rangers, Minnesota Twins, and Boston Red Sox from 1982 to 1989.

The game was suspended after 32 innings, and resumed June 23; Smithson's PawSox won it in the bottom of the 33rd frame.

After attending spring training with the 1982 Red Sox, Smithson was traded to the Rangers on April 9 for left-handed relief pitcher John Henry Johnson.

He was recalled by the Rangers from the Triple-A Denver Bears and began his MLB career late in August as a starting pitcher—the role he would play for much of his big-league tenure.

The Red Sox brought Smithson back as a free agent in 1988, and he spent two seasons with them as a swing man, making 37 starts in 71 games.