Tom Hiddleston as Charles 'Chuck' Krantz

Jacob Tremblay as Charles 'Chuck' Krantz (teen)

Benjamin Pajak as Charles 'Chuck' Krantz (pre-teen)

Cody Flanagan as Charles 'Chuck' Krantz (child)

Nick Offerman as Narrator (voice)

Chiwetel Ejiofor as Marty Anderson

Karen Gillan as Felicia Gordon

Annalise Basso as Janice Halliday

Mia Sara as Sarah Krantz

Mark Hamill as Albie Krantz

Samantha Sloyan as Miss Rohrbacher

Trinity Bliss as Cat McCoy

David Dastmalchian as Josh

Matthew Lillard as Gus

Kate Siegel as Miss Richards

Rahul Kohli as Bri

Harvey Guillén as Hector

Saidah Arrika Ekulona as Andrea

Carl Lumbly as Sam Yarbrough

Taylor Gordon as Taylor Franck

Michael Trucco as Dylan's Dad

Q'orianka Kilcher as Virginia 'Ginny' Krantz

Violet McGraw as Iris

Andrew Grush as Mac

Heather Langenkamp as Vera Stanley

Amy Biedel as Dylan's Mom

Franklin Ritch as Brent

Antonio Raul Garcia as Brian Krantz

Molly C. Quinn as Chuck's Mother

Lily Rose Lumpkin as Clerk

Sauriyan Sapkota as Ram

Mackenzie Gwaltney as Student #2

Anne Russell West as Student #3

Kyler Alan Collvins as Timmy

Mike Flanagan as Mourner

Matt Biedel as Doctor Winston

Carla Gugino as News and Commercial Voice (voice)

Elan Gale as Radio News Reporter (voice)

Eric Vespe as Radio Host #1 (voice)

Scott Wampler as Radio Host #2 (voice)

Hamish Linklater as American Reporter (voice)

Axelle Carolyn as French Reporter (voice)

Sandra Hess as German Reporter (voice)

Alexa Bolter as UK Reporter (voice)

Lauren LaVera as Italian Reporter (voice)

Mikki Levi as Japanese Reporter (voice)

Raymond Garcia as Spanish Reporter (voice)

Trevor Macy as Mourner (uncredited)