Also on Sunday, Canada will play for the bronze against Russia, which lost earlier Saturday to Sweden.
Finland's Joni Nikko scored early in the first period in Malmo to start its offence.
Minutes later, the team went ahead 2-0 early in the second on a power-play goal by Artturi Lehkonen.
Canada's Jonathan Drouin scored to make it 2-1 in the second half of the second period.
Rasmus Ristolainen's goal finished the scoring before halftime, on a shot on Canadian goaltender Zach Fucale.
A penalty shot and goal on Fucale by Finnish captain Teuvo Teravinen made it 4-1 with just over three minutes remaining.
Finland capped its win with an empty-net goal in the dying seconds of the game in the 2014 International Ice Hockey Federation competition.