John Andrew Charles Kucek (born June 8, 1953), or JACK for short, is an American former Major League Baseball (MLB) pitcher who played for the Chicago White Sox, Philadelphia Phillies, and Toronto Blue Jays from 1974 to 1980.

A native of Warren, Ohio, Kucek attended Newton Falls High School and Miami University.

Kucek quickly worked his way up from the Class A Appleton Foxes to the Major Leagues, and made his White Sox debut on August 8, 1974 as a reliever against the California Angels.

Kucek played the majority of the 1979 season for the Phillies' Triple-A affiliate, the Oklahoma City 89ers, and was released in December of the same year.

In 1981, however, Kucek spent the entire year in the Blue Jays minor league system at Syracuse then retired after the season.