That's easy - Sidney Crosby. After all, the League itself has parroted the fact (and markets the claim) and the meme has more or less become a commonly-accepted part of modern hockey lore, so it must be right, right?
Back in January of 1984, Brian Bellows first wore the "C" for the Minnesota North Stars and continued to do so for the remainder of the 1983-84 season (Bellows was the interim captain while Craig Hartsburg was out with a lengthy injury). Bellows was
The fact that Crosby was the youngest "permanent" captain in League history can't be debated - but neither can the fact that Brian Bellows was the youngest captain in NHL history.