Joy Bryant

Helen Grace

Noah Cottrell

Simon Grace

Lyon Daniels

Jared Grace

Mychala Lee

Mallory Grace

Jack Dylan Grazer

Thimbletack (voice)

Christian Slater

Mulgarath / Dr. Dorian Brauer

Alyvia Alyn Lind

Calliope

Charlayne Woodard

Lucinda Spiderwick

Aria Mia Loberti

Valentina

Patty Guggenheim

Stacy Varnow

Hunter Dillon

Hatcher

Momona Tamada

Emiko Noizumi

Mellany Barros

Bree Kent

Dylan Bruce

Tanner Kent

Keith Arbuthnot

The Ogre

Dylan French

Fencing Attendant #1

Genevieve Lam

Gas Station Attendant

Sophia Noella

Young Melvina

Jazlyn Onaba

6-Year-Old Helen

Favour Onwuka

Young Lucinda

Skovensky Moline Valeus

Orderly

Teagan Vincze

Snooty Saleswoman

Nicholas Zhang

Fencing Attendant #2

Albert Jones

Arthur Spiderwick

Jed Rees

Hubert

Adina Insley

6-Year-Old Lucinda

Newsha Richards

Yalda

Arlene Duncan

Melvina

Jack Irwin

Aiden

Mack Gordon

Husband

Margarita Iturriaga

Injured Mom

Dylan Colton

Chris

Emma Leduc

Thalia

Tate Ennis

Hind

Winson Won

EMT

Terry Chen

Zao

Jeff Sanca

Mustached Bus Driver

Sari Mercer

Cobweb

Jericho Cabinas

Peasblossom

Jared Ager-Foster

Mustardseed

Cindy Piper

Mahjong Lady #1

Jasmin Dring

Mahjong Lady #2

Ricky Lee

Shopkeeper

Medina Hahn

City Council President

Rhys Coiro

Richard Grace (voice) (uncredited)

Ethel Pitchford

Barbara Hatcher

Janet Gigliotti

Nurse

Joshua Pak

Bruce