Wunder

Jacob Tremblay

Auggie

Julia Roberts

Isabel

Owen Wilson

Nate

Izabela Vidovic

Via

Noah Jupe

Jack Will

Millie Davis

Summer

Bryce Gheisar

Julian

Mandy Patinkin

Mr. Tushman

Danielle Rose Russell

Miranda

Daveed Diggs

Mr. Browne

Mark Dozlaw

Teenage Doctor

Rukiya Bernard

Nurse

Elle McKinnon

Charlotte

Ty Consiglio

Amos

Kyle Breitkopf

Miles

James A Hughes

Henry

Ali Liebert

Ms. Petosa

Cameron Roberts

Cute Guy

Nadji Jeter

Justin

Ben Immanuel

Mr. Davenport

Jason McKinnon

School Photographer

Sônia Braga

Grans

Nicole Oliver

Jack Will's Mom

Emily Delahunty

Ximena Chin

Sasha Neuhaus

Maya

Rachel Hayward

Miranda's Mom

Grayson Maxwell Gurnsey

Our Town Player

Yan-Kay Crystal Lowe

Julian's Mom

Steve Bacic

Julian's Dad

Jason Tremblay

Camp Counsellor

Emma Tremblay

Michelle

Lidya Jewett

Lina Annan

Gidget

Daisy

Andre Robinson

School Kid (uncredited)

Jennifer March

Neonatologist

J. Douglas Stewart

Darth Sidious

Joseph Gordon

Dodgeball Player

Erika McKitrick

Ella

Izzy Lieberman

Reid

Hannah Hoberman

Rebecca

Michael Alan Healy

Chewbacca

Lucia Thain

Savanna

Callahan Brebner

Guy on Bus

Caleb Gordon

Our Town Player

Emily Giannozio

Our Town Player

Haley Goldin

Our Town Player

Maccie Margaret Chbosky

Via (Age 4)

Victoria V. Cruz

Science Fair Judge

William Dickinson

Eddie

Armen Bagdasarov

Danny

Kaelyn Breitkopf

Angela

Brayden Snow

Classmate (uncredited)

Alyssa Andronyk

School Kid (uncredited)

Wilson Chieng

Simon Stimson (uncredited)

Dallas Snow

Classmate (uncredited)

Justin Snow

Classmate (uncredited)

Kayzhia Snow

Classmate (uncredited)

Amber Snow

Classmate Parent (uncredited)

Elayna Sing

Classmate (uncredited)

Ann Evans

Parent (uncredited)

Abigail Friend

Daughter at Coney Island Beach (uncredited)

Razvan Orban

Boy in Red (uncredited)

Kari Staten

Parent (uncredited)