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