Variety.com said Saoirse Ronan has also signed on to headline the movie for which DeVito penned the screenplay, based on Avi's young adult book.
DeVito, who will also direct, is expected to start shooting in September.
Ronan, a young Irish actress who garnered raves for her performance in "Atonement" last year, is to play the title character in "Charlotte," Variety.com said.
The film will follow the teen as she makes a trans-Atlantic crossing from England to the United States in the 1830s.
Brosnan, who will soon be seen in "Mamma Mia!," will play a ruthless captain, while Freeman will play the ship's cook, who looks after Charlotte, the entertainment industry trade paper said.