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