Sweden started out strong. Forward Filip Sandberg put the team ahead in the second period.
But the US turned the game, with Rocco Grimaldi scoring twice in a three-minute span and Vince Trochek adding an empty-net goal in the final seconds.
Despite massive pressure from Sweden towards the end of the game, the team failed to get the puck past US goalie John Gibson.
Saturday's final marks 12 straight wins for the United States against Sweden. It has been 17 years since Sweden won against the US in the World Junior Ice Hockey Championships.
Sweden won 11 WJHC games in a row after losing the bronze medal to the United States in Buffalo in 2011.
Saturday's loss meant the Swedes failed to defend the gold taken in last year's final victory against Russia in Calgary.
It was the third title for the Americans, who also won in 2004 and 2010.
American goalie John Gibson made 26 saves for the victory and was named the MVP of the tournament. Niklas Lundström had 31 saves for Sweden.
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Sweden will get the chance to reclaim the title on homeground at the next WJCH, which will be held in Malmö.
But it will be without team captain Roger Rönnberg. He is being replaced by assistant coach Rikard Grönborg.
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