Freddie Highmore

as Arthur Montgomery

Mia Farrow

as Granny

Robert Stanton

as Armand

Penny Balfour

as Rose Montgomery

David Gasman

as The Mechanic

Antony Hickling

as Douglas

Dashiell Eaves

as Simon

Joseph Rezwin

as Brad

Cooper Daniels

as George Lucas

Ron Crawford

as Archibald

Stuart Rudin

as Francis

Steve Routman

as Dr. Stitch

Peter Hudson

as General Montgomery

Lou Reed

as Maltazard (voice)

Selena Gomez

as Selenia (voice)

Iggy Pop

as Darkos (voice)

Mike Powers

as Grafitti Artist (voice)

James A. Baffico

as Martin Baltimore (voice)

Jean Bejote Njamba

as Bogo Chief

Laurent Mendy

as Bogo

Norman Stokle

as Mayor