The victory gives the Americans only their second Gold medal in tournament history and snaps Canada's streak of five straight Gold medals.
It appeared as though all the momentum was on the Canadian's side after Jordan Eberle, who was named tournament MVP, scored twice with less than three minutes remaining in regulation to force the extra frame. Just over four minutes into overtime Carlson beat Martin Jones for his second of the game setting off wild celebrations by the Americans.
USA 6 CANADA 5 - BOXSCORE
If a classic encounter on New Year's Eve between the two sides could be considered the appetizer, than this title bout was a full five course meal.
A packed house at the First Credit Union Centre in Saskatoon was treated to a wide open encounter that saw both starting netminders get pulled as the tournament's two top teams battled tooth-and-nail for Junior hockey supremacy.
Luke Adam got Team Canada on the board early in the first period by shoveling a backhand past Mike Lee for his fourth goal of the tournament on a great feed from Jordan Caron.
Team USA then rallied as Chris Kreider beat Jake Allen high stick side to pull the Americans even. Just 36 seconds later Jordan Schroeder gave the Stars and Stripes their first lead by beating Allen for his third of the tournament.
Canada responded immediately when Nazem Kadri found Calgary Flames first round pick Greg Nemisz who found the back of the net for the first time in the tournament to square things up at two apiece.
The ongoing Canadian theme of undisciplined play continued when defenceman Alex Pietrangelo drilled Jeremy Morin from behind, picking up a 10-minute misconduct as the opening frame drew to a close.
It was a big loss for Canada who were playing the game without their top shutdown defender in Travis Hamonic who suffered a separated shoulder in the dying moments of the semifinal game against Switzerland.
Handed the man advantage, the Americans came flying out of the gate to open the second period as Washington Capitals' prospect Carlson beat Allen with a point blast to give Team USA the lead once again.
That advantage was short lived as likely first overall pick in the upcoming NHL entry draft Taylor Hall responded with his sixth of the tournament to chase Lee from the American net.
Tied at three Calgary Hitmen sniper Brandon Kozun had a great opportunity to give the Canadians an early third period lead when his shot beat Campbell but not the crossbar to keep things even.
Canada were once again offered an excellent chance to take control when Philip McCrae was penalized for delay of game after flipping the puck over the glass, however the Americans repeatedly killed off scoring chances thanks to stellar netminding by Campbell.
That seemingly sparked the Americans as moments later they broke in on an odd man rush with Jerry D'Amigo firing home his sixth of the tournament.
With the Canadians on their heels, Derek Stepan administered what could have been the kill shot as he pounced a loose puck coughed up by Jake Allen to give the Americans an insurance marker.
The goal chased Allen from the Canadian net. He was replaced by Martin Jones, the Calgary Hitmen netminder.
That decision by Canadian head coach Willie Desjardins was all the inspiration that Canada would need as Eberle then put the team on his shoulders.
If the Edmonton Oilers' prospect built his reputation for being a clutch performer during last year's Gold medal game, he further cemented his position with a pair of goals late in regulation to help Canada rally from two goals down and force overtime.
With just under three minutes remaining Eberle took a feed from Pietrangelo and fired his seventh of the tournament past Campbell to pull the Canadians within one.
Not satisfied there, just over a minute later Eberle pounded home his second of the period and forcing overtime for the second consecutive year in the Gold medal game.
The was Eberle's 14th goal all-time in the tournament, surpassing John Tavares for the Canadian lead.
While the momentum was on the side of the Canadians, Team USA refused to wilt. Carlson broke in on a three on two and fired home his fourth goal of the tournament to secure the first medal of any colour by the Americans since 2007 and only their second Gold to go along with their victory over Canada in 2004.
Earlier in the day the Swiss were hammered 11-4 by Sweden in the Bronze medal game.