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