Julia Roberts to play mum to Jacob Tremblay in tearjerker Wonder

Tremblay will play a facially-deformed fifth grader who attends school for the first time

Jacob Tremblay was the talk of tinsel town last awards season for his starring role in Room (Getty Images)

Move over Brie Larson, Jacob Tremblay has a new Hollywood mum.

The 9-year-old actor has been cast opposite Julia Roberts in the film adaptation of moving mother and son story Wonder by author RJ Palacio.

Tremblay will play facially-deformed fifth-grader Auggie Pullman, who finally enters mainstream schooling after a lonely life being taught at home by his mum.

Palacio wanted to write the 2012 bestseller to raise awareness among children of how people with deformities are treated in society. She was inspired after visiting an ice-cream shop with her three-year-old son and worrying how he might react to a child with a facial deformity in the queue.

Palacio told NPR that Auggie “really doesn’t dwell” on his physical features. “What he looks like, in a sense, is very incidental to him,” she said. “What he dwells on is the reaction that people have to him because all he wants is to be an ordinary kid. But he really can’t because he’ll always have people staring at him and reacting to him in a certain way.

“You’re really rooting for the kids who stand up for Auggie . Ultimately, it's a feel-good book because it is a meditation on kindness and the impact of kindness.”

Stephen Chbosky, known for The Perks of Being a Wallflower, is directing from a script by Steve Conrad.