Freddie Highmore … Jared Grace / Simon Grace
Mary-Louise Parker … Helen Grace
Nick Nolte … Mulgarath
Sarah Bolger … Mallory Grace
Andrew McCarthy … Richard Grace
Joan Plowright … Aunt Lucinda Spiderwick
David Strathairn … Arthur Spiderwick
Seth Rogen … Hogsqueal (voice)
Martin Short … Thimbletack (voice)
Jordy Benattar … Young Lucinda
Tod Fennell … Helen’s Co-Worker
Mariah Inger … Nurse
Jeremy Lavalley … Tow Truck Driver
Lise Durocher-Viens … Mrs. Spiderwick
Tyler Patrick Jones … Additional Performer

Director:

Mark Waters