Run Fatboy Run

Simon Pegg

Dennis

Thandiwe Newton

Libby

Hank Azaria

Whit

Dylan Moran

Gordon

Harish Patel

Mr. Goshdashtidar

India de Beaufort

Maya Goshdashtidar

Matthew Fenton

Jake

Simon Day

Vincent

Ruth Sheen

Claudine

Nevan Finegan

Mickey

Tyrone Huggins

Grover

Iddo Goldberg

News Reporter

Ameet Chana

Taxi Driver

Chris Hollins

Himself

Denis Lewis

Herself

Sutara Gayle

Nurse

Gabriel Fleary

Drag Queen

Pandora Colin

Claire

Stephen Merchant

Man with Broken Leg

David Walliams

Man in Bakery

Hazel Douglas

Older Woman

Anna Tolputt

Receptionist

Simon Lenagan

Undercover Cop / Dad

David Cann

Marathon Official

T.R. Bowen

Doctor

Margaret John

Libby's Grandmother

Floella Benjamin

Libby's Mum

David Milner

Libby's Dad

Henrietta Clemett

Reception Nurse

Peter Serafinowicz

TV Commentator

Preston Nyman

Boating Boy (uncredited)

Rene Costa

Spectator (uncredited)