Paul Terry
James Henry Trotter
Miriam Margolyes
Aunt Sponge / Glowworm (voice)
Joanna Lumley
Aunt Spiker
Pete Postlethwaite
The Magic Man
Simon Callow
Grasshopper (voice)
Richard Dreyfuss
Centipede (voice)
Jane Leeves
Ladybug (voice)
Susan Sarandon
Miss Spider (voice)
David Thewlis
Earthworm (voice)
Steven Culp
James' Father
Susan Turner-Cray
James' Mother
Cirocco Dunlap
Girl with Telescope
Kathryn Howell
Woman in Bathrobe
Mike Starr
Cop
Michael Girardin
Reporter #1
J. Stephen Coyle
Reporter #2
Tony Haney
Reporter #3
Mario Yedidia
Street Kid
Jeff Mosley
Hard Hat Man
Jeff Bennett
Centipede (singing voice) (uncredited)
Sally Stevens
Glowworm (singing voice) (uncredited)