Wozniacki, the No. 1 seed, defeated eighth-seeded Ekaterina Makarova 6-1, 5-7, 6-4. Wozniacki faced just one break point outside of the seesaw second set, which had a total of seven breaks.
She lost only four points on serve in winning the first set and 10 over five games in the decisive third.
Kanepi, seeded third, got by sixth-seeded Varvara Lepchenko 6-4, 2-6, 6-4. Kanepi used three breaks to claim the first set and had one in the third, when she didn't see a break point against her.
Kanepi is playing in her first tournament since the French Open due to an Achilles tendon injury.
Wozniacki is 3-2 in her career versus Kanepi but Kanepi won their only meeting to date in 2012, taking a three-set decision at the French Open. Wozniacki is 18-11 in WTA title matches but she hasn't won a final since August 2011. Sunday's match will mark her second final of 2012. Kanepi is looking for her third title of 2012 and fourth overall.
The Korea Open winner will earn $112,300 with the runner-up taking home $57,665. Makarova and Lepchenko each won $30,959 as semifinalists.