The bout will headline The Ultimate Fighter Brazil Finale at Ibirapuera Gymnasium. UFC officials confirmed the new main event on Tuesday.
Maldonado (21-6) replaces former UFC champion Junior dos Santos, who was forced to withdraw from the bout earlier this week due to a hand injury. The Brazilian is 4-3 all time in the UFC. All seven fights have been at 205 pounds.
A former professional boxer, Maldonado is currently riding a three-fight win streak. The 34-year-old is coming off a unanimous decision over Gian Villante in March.
Miocic (11-1) will look to build on back-to-back decision wins over veterans Roy Nelson and Gabriel Gonzaga. Fighting out of Euclid, Ohio, Miocic, 31, is the No. 5-ranked heavyweight in the world, according to ESPN.com.