Jim Lonborg is a former right-handed starting pitcher. He played for several teams over his fifteen year career but his most notable and successful seasons came while playing for the Boston Red Sox. In 1967, Lonborg would lead the league with 22 wins, 39 starts and 246 strikeouts. At the end of the season he was named the American League Cy Young award, becoming the first Rex Sox player to win the award. he ended his career with 157 wins, 1475 strikeouts, a 3.96 ERA and 2464.1 innings pitched.

Lonborg was inducted into the Red Sox Hall of Fame in 2002 and has worked in the non-profit industry since retiring.