A straight-sets victory over the Serbian saw the British No 3 triumph 6-1, 6-4, with Italian Andreas Seppi awaiting him in the final following his 6-3, 6-4 win over Jason Jung, of Chinese Taipei, ending his dream run after entering the oturnament as a qualifier.
Kecmanovic, the No 6 seed for the tournament fell to Edmund, seeded eighth this week in 72 minutes.
Edmund, seeded eighth, told the ATP website: “This is great to be back in a final, playing the matches you want to be playing.
“I obviously want to go all the way, but I’m enjoying my tennis. I’ve kept improving and learning with each match.”
Edmund’s last success came in Antwerp in 2018 and he reached his first final since then with an impressive display at the Nassau Coliseum.
The 25-year-old won the first five games as he eased through the first set.
Kecmanovic, ranked 54th in the world, stayed with Edmund in the second set until the Briton broke to love to go 5-4 up before serving out the match.