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