Seventh-seeded Kecmanovic defeated US third seed Alex Michelsen 7-6, 6-3 while eighth seed Davidovich Fokina ousted Italian fourth seed Matteo Arnaldi 6-4, 6-4.
Kecmanovic, a 25-year-old Serbian who was a 2023 Delray Beach runner-up, will be playing in his fifth tour-level final. His lone title came at Kitzbuhel in 2020.
Davidovich Fokina had upset world number four Taylor Fritz, ending the American's bid for a third straight title at the South Florida event.
The 25-year-old Spaniard dispatched Arnaldi in one hour and 42 minutes to reach his second ATP final, having dropped the first at the 2022 Monte Carlo Masters to Greece's Stefanos Tsitsipas.
In bright sunshine, Kecmanovic bounced back from wasting two set points when serving at 6-5 in the first set to eventually win the tiebreak.
In the second set, he saved both break points he faced to advance after 90 minutes.