On November 27, 2012, it was announced that Lionsgate was developing the feature film adaptation of R. J. Palacio's debut novel Wonder, while in talks with John August to write the screenplay.[5] Mandeville Films' David Hoberman and Todd Lieberman would be producing the film.[5] On May 8, 2013, Jack Thorne was hired to adapt the novel, while August, who was previously reported as writer, had departed from the project.[6] In October 2014, John Krokidas was reported to be directing the film,[7] but in April 2015, Paul King was hired to take the directing duties. Steven Conrad was writing the script at that time.[8]

On April 14, 2016, Jacob Tremblay was cast in the film to play the lead role as Auggie Pullman, while Julia Roberts was in talks to play Auggie's mother.[9] On May 5, 2016, Roberts was confirmed to play the mother, with Stephen Chbosky signed on to direct the film.[10] On June 27, 2016, Owen Wilson had joined the film to play Auggie's father.[11] On July 11, 2016, newcomer Noah Jupe joined the film to play Auggie's best friend at school.[12] On July 15, 2016, Daveed Diggs was cast in the film to play Mr. Browne, an English teacher at the school.[13] On August 19, 2016, Sonia Braga joined the cast of the film, portraying the role of Roberts' character's mother.[14]

Jacob's prosthetic makeup, designed and created by Arjen Tuiten, took an hour and half to apply. It consisted of a skull cap with prosthetic ears attached, a facial prosthetic that covered Jacob's face, and a wig to tie it all together.[perlu rujukan]

Marcelo Zarvos composed the film's score.[15]