Jack Dempsey Cassini (October 26, 1919 – September 20, 2010) was an American professional baseball infielder, manager and scout. Born in Dearborn, Michigan, he was a six-time stolen base champion during his minor league playing career (1940–41; 1946–55) and stole 378 bases lifetime. Cassini then fashioned a long career as a minor league manager and MLB scout. He skippered teams in the Chicago White Sox, Cincinnati Reds, New York Mets and Cleveland Indians farm systems, and scouted for Cincinnati, the Mets and Cleveland.