Jagodina advanced to their first final with a 4-1 home rout of Javor Ivanjica which overturned a 1-0 first-leg deficit.
OFK levelled the tie on aggregate when Milos Mijic swept home a rebound shortly after the break but defender Nemanja Radoja struck on the hour for Vojvodina, who have lost all their five previous finals.
Goran Gogic fired Jagodina ahead in the 13th minute before midfielder Marko Momcilovic put Javor levelled the score with a diving header six minutes later.
Jagodina were 2-1 up on the night after Radoslav Vlasic put the ball into his own net and nosed ahead on aggregate with a superb Milos Stojanovic header in the 34th minute.
Milos Lepovic sealed Jagodina's triumph on the hour with a stinging low shot and their coach Simo Krunic heaped praise on his players after the final whistle.
"The lads really wanted this final and I can only congratulate them for a spirited and gritty performance from start to finish," Krunic told Serbia's Arenasport television.
"We didn't buckle after falling behind on aggregate and the team didn't put a foot wrong after needing to score at least twice to go through."
The final will be played in Belgrade on May 8.