Jack Franklin Whillock (November 4, 1942 – December 20, 2021) was a right-handed Major League Baseball pitcher who spent seven games with the Detroit Tigers in 1971. After attending the University of Arkansas, Whillock was signed by the St. Louis Cardinals prior to the 1964 season. In October 1968, he was released by the Cardinals, and sometime before the 1969 season he was signed by the Tigers. He made his major league debut with the Tigers on August 29, 1971 at the age of 28. He made seven relief appearances for them, going 0-2 with a 5.63 ERA, allowing ten hits and two walks in eight innings of work. On September 21 he appeared in his final game.