Bellator has yet to determine where the event will take place.
"This will be an offensive clinic between two devastating finishers," Bellator CEO Bjorn Rebney said. "Both Pat Curran and Patricio Pitbull can finish with relentless strikes or vicious submissions.
"This is a fight between two of the best featherweights in MMA and will be a title fight to remember."
Curran (17-4) claimed the featherweight title March 9 with a third-round knockout of then-champion Joe Warren.
Since a failed bid to wrest the lightweight belt from Eddie Alvarez in April 2011, Curran returned to his natural 145-pound weight class and has put together a four-fight win streak.
Freire (17-1) earned his title shot with a unanimous decision on May 21, 2011, over Daniel Straus in the Bellator Season 4 featherweight tournament final.