Auggie's facial disease is called mandibulofacial dystosis, also known as "Treacher Collins syndrome."
Jacob Tremblay and his family went to the Children's Craniofacial Association retreat, where he got to meet and befriend children with Treacher Collins syndrome, the same syndrome that Auggie has.
R.J. Palacio got the inspiration to write the book after taking her son out for ice cream, where they saw a child with Treacher Collins Syndrome. Her son cried at the sight of this boy. This story is used in a scene from the film, where Jack Will's mother is reminding him why it's important to make Auggie feel welcome.
Jacob Tremblay'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.
Siblings Jacob Tremblay and Emma Tremblay are both featured in this movie together. Their father, Jason Tremblay, is also in the movie.
The bicycle that August is riding in the film is the same bicycle that Elliot is seen riding in the movie E.T.
The second film based off a novel to be directed by Stephen Chbosky. The first was The Perks of Being a Wallflower (2012).
Miranda's nickname for Auggie is "Major Tom". This is taken from the David Bowie song "Space Oddity", which is about an astronaut named Major Tom.
The second film adaptation of a novel in which it is narrated from the perspective of a child played by Jacob Tremblay, the first being Room (2015).
Paul King was originally going to direct, but he dropped out in order to work on Paddington 2 (2017).
Izabela Vidovic (Via) and Emma Tremblay (Michelle) both are also in the third season of Supergirl (2015): Vidovic as the young Kara Danvers and Tremblay as Ruby, Samantha Arias' daughter.
The character of Auggie loves Star Wars. Jacob Tremblay in real life is also a huge fan of Star Wars.
The scene where Isabel (Julia Roberts) and Nate (Owen Wilson) are drinking wine towards the end of the movie contains a Pretty Woman homage. Julia Roberts opens a hinged gift box and laughs out loud, just as her character did in Pretty Woman when Richard Gere gives her a necklace.
Special makeup effects designer and artist Arjen Tuiten hopes that the makeup that he created does justice for the original book.
One of the first full-length feature films ever to feature the rebuilt World Trade Center Freedom Tower (the blue glass-looking skyscraper in the background of most of Wonder's aerial shots of New York).
The second film in which Julia Roberts plays a character named Isabel, the first being Stepmom (1998).
Julia Roberts and Mandy Patinkin worked together on Smurfs: The Lost Village (2017).
A film installment based on a young adult book franchise has been released in November every year since 2008. The Twilight Saga was released in 2008, 2009, 2011 and 2012. The Hunger Games series was released in 2013, 2014, and 2015, and the Harry Potter/J.K. Rowling's Wizarding World series in 2010, and 2016. Wonder is the first film adaptation based on a children's novel in this slate.