The film also stars "Room" actor Jacob Tremblay, who plays Auggie Pullman, a young boy born with a rare genetic disorder named Treacher Collins, reported Contactmusic.
The 50-year-old actor plays the role of Tremblay's mother in the movie.
"To me, 'Wonder' is a superhero movie because Auggie is a superhero. It stopped me in my tracks. I read it with my kids, I loved it, they loved it. I hurled myself on the mercy of the producers and said, 'Please, let me be in this movie. I want to be the mom'," said Roberts.
Directed by Stephen Chbosky, the movie also stars Own Wilson.