The film already stars Tom Hiddleston, Brie Larson and Mitchell's "Straight Outta Compton" co-star Corey Hawkins, said The Hollywood Reporter.
Jordan Vogt-Roberts will direct the picture, and Legendary's Thomas Tull and Jon Jashni will produce with Mary Parent.
Alex Garcia and Eric McLeod will serve as exec producers. Max Borenstein, John Gatins and Dan Gilroy penned the script.
While plot details are still vague, the story will be set in the mysterious, dangerous home of the king of the apes as a team of explorers ventures deep inside the island. Mitchell will play a pilot in the pic.