The top seed needed just an hour and two minutes to see off Kanepi 6-1 6-0, the Dane allowing her opponent just one hold of serve which came in the fifth game of the match.
Wozniacki had needed three sets to defeat Russia's Ekaterina Makarova in yesterday's semi-final, but there was no element of fatigue holding her back on Sunday.
The world number 11 told wtatennis.com: "Yesterday [Saturday] was a very difficult match, but the final is the final, and you just do anything you can to win.
"Today [Sunday] I did well at turning defence to offence and offence to defence. That's actually a strength of mine.
"I'm very pleased with how everything turned out."
The Seoul title marked the former world number one's first tour triumph since August 2011 but she was eager to play down talk of a swift rise back up the rankings.
"I want to enjoy it and be positive so that's what I'm thinking about right now," she added.
"I want to build up for the next season and hopefully my results this week will help me move forward and get back to playing my best."