Näyttelijät

• Freddie Highmore — Jared Grace
• Freddie Highmore — Jared Grace
• Sarah Bolger — Mallory Grace
• Joan Plowright — Aunt Lucinda Spiderwick
• Mary-Louise Parker — Helen Grace
• Nick Nolte — Mulgarath
• David Strathairn — Arthur Spiderwick
• Andrew McCarthy — Richard Grace
• Martin Short — Thimbletack (voice)
• Seth Rogen — Hogsqueal (voice)
• Tyler Patrick Jones — Additional Performer
• Ron Perlman — Red Cap (voice)