John Cleo "Jack" Shaffer (August 13, 1909 – June 17, 1963) was an American professional basketball player.
He appeared in six games for the Akron Firestone Non-Skids in the National Basketball League during the 1937–38 season.
A son of Russian immigrants, he grew up in Grand Island, Nebraska and attended the Grand Island campus of Doane University before enrolling at DePaul University.