Keira Knightley
Georgiana Cavendish, Duchess of Devonshire
Ralph Fiennes
Duke of Devonshire
Charlotte Rampling
Lady Spencer
Dominic Cooper
Charles Grey
Hayley Atwell
Bess Foster
Simon McBurney
Charles Fox
Aidan McArdle
Richard Brinsley Sheridan
John Shrapnel
General Grey
Alistair Petrie
Heaton
Patrick Godfrey
Dr. Neville
Michael Medwin
Speechmaker
Justin Edwards
Macaroni
Richard McCabe
Sir James Hare
Calvin A. Dean
Devonshire House Servant (as Calvin Dean)
Hannah Stokely
Devonshire House Maid
Andrew Armour
Burleigh
Emily Jewell
Nanny
Bruce Mackinnon
Sir Peter Teazle
Georgia King
Lady Teazle
Luke Norris
Footman
Eva Hrela
Charlotte (Age 3)
Poppy Wigglesworth
Charlotte (Age 9)
Emily Cohen
Harryo
Mercy Fiennes Tiffin
Little G
Sebastian Applewhite
Augustus
Angus McEwan
Lord Robert
Kate Burdette
Lady Harriet
Laura Stevely
Lady Elizabeth
Benjamin Noble
Lord Ambrose (as Ben Garlick)
Max Bennett
Lord Walter
Camilla Arfwedson
Lady Charlotte
Fiona Sheehan
Young Girl in Theatre
Sarah Wyatt
Servant Girl
Thomas Arnold
Dealer
Gilbert Wynne
Althorpe Servant
Richard Curzon
Heaton's Clerk
Sophia Johnston
Guest at Lady Melbourne's Ball
Katerina Tana
Guest at Lady Melbourne's Ball
Clive Pearse
Narrator