Armand "Bep" Guidolin is and almost certainly always will be known as the youngest player to ever perform in the National Hockey League.
When he debuted with the Boston Bruins on November 12th of 1942, he was just 16 years old! Due to war-time player shortages the Bruins used several youngsters that season. Guidolin played on a line with 17 year old Don Gallinger and 20 year old Bill Shill. With the famed "Kraut Line" of Milt Schmidt, Woody Dumart and Bobby Bauer absent from the Bruins line up due to war commitments, the Boston press was quick to dub the rookie line as the "Sprout Line."
Guidolin spent 4 seasons with the B's, though he missed the 1944-45 season due to his own military service. He later played with Chicago and Detroit in the NHL before rounding out his career with several seasons in the minor leagues. By 1958 he was reinstated as an amateur in Canada and helped the Belleville McFarlands win the Allan Cup.
Read the full Bep Guidolin biography, including his impact on Wayne Gretzky's Edmonton Oilers