Grace VanderWaal

Susan "Stargirl" Caraway

Graham Verchere

Leo Borlock

Karan Brar

Kevin Singh

Maximiliano Hernández

Mr. Robineau

Darby Stanchfield

Gloria Borlock

Giancarlo Esposito

Archie Brubaker

Collin Blackford

Benny Burrito

Annacheska Brown

Tess Reed

Shelby Simmons

Hillari Kimble

Allison Wentworth

Dori Dilson

Artemis

Mallory Franklin

Gabriella Surodjawan

Kim

John Apolinar

Wayne Parnell

Alex James

Zack James

Enzo De Angelis

Leo Age 8

Sara Arrington

Ana Caraway

Lucinda Marker

Principal Sutters

Hannah Kauffmann

Band Leader

Gavin White

Big Kid #1

Troy Brookins

Ron Kovac

Ryan Begay

Mud Frog Fan

Damian O'Hare

Leo's Dad

Orion Carrington

Young Male Teacher

J. Nathan Simmons

Fan (uncredited)

Shylo Molina

Talent Show Magician (uncredited)

Alexander Alayon Jr.

High Schooler (uncredited)