Jamaica's Bucknor, standing in a record fifth successive final, and Pakistan's Dar are joined by South Africa's Rudi Koertzen and New Zealander Brent Bowden as third and fourth umpires.
The 60-year-old Bucknor tops the list for standing in successive finals ahead of England's Dickie Bird and David Shepherd, who each umpired three finals.
"It is a dream come true," Bucknor said in an ICC news release announcing his appointment. "I was happy knowing I was umpiring in a Cricket World Cup in the Caribbean and now being asked to stand in the final again makes it even more special."
Dar, 38, is standing in his first World Cup final. Former New Zealand captain Jeff Crowe will be the match referee.