Kate Beckinsale Catherine
Robin Williams Dennis the Dog (voice)
Simon Pegg Neil Clarke
Michael Palin Kindly Alien (voice)
Eddie Izzard Headmaster
Joanna Lumley Fenella
John Cleese Chief Alien (voice)
Rob Riggle Grant
Bill Jones Producer
Emma Pierson Miss Pringle
Gavin Scott Newsreader, Screenplay
Terry Gilliam Nasty Alien (voice)
Judy Loe Canteen Lady
Sanjeev Bhaskar Ray
Eric Idle Salubrious Gat (voice)
Robert Bathurst James Cleverill
Terry Jones Director, Scientist Alien (voice) / Van Driver, Writer
Meera Syal Fiona
Marianne Oldham Rosie
Brian Cox Self
Alexa Davies Sandwich Girl
Neville Phillips Author
Lucy Cork Stunt Double
Naomi Moore Set Decoration
Peter Hannan Director of Photography
Ronan Summers Security Man
Mike Medavoy Executive Producer
James Acheson Costume Design, Production Design
Irene Lamb Casting
George Fenton Original Music Composer
Ben Timlett Producer
James Kermack Policeman
Jennifer Bell Hairstylist
Jud Charlton Mortician
Julian Rodd Editor
David Annen Newsreader
Oriol Navarro Animation
Lennon Clarke Bank Robber
John Kay Animation
Martyn Smith Animation
Mairi McHaffie Newsreader
Du Wenlong Animation
Rob Hemmings Animation Director
Xu Yueyuan Animation
Dong Yixue Animation
Tan Weijian Animation
Yan Yan Animation
Xie Liyan Animation
Sun Xiaoxuan Animation
Li Jingxin Animation
Beranger Maurice Animation
Matt Fidler Animation