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

Simon McBurney

Character: Charles Fox

Aidan McArdle

Character: Richard Brinsley Sheridan

John Shrapnel

Character: General Grey

Alistair Petrie

Character: Heaton

Patrick Godfrey

Character: Dr. Neville

Michael Medwin

Character: Speechmaker

Justin Edwards

Character: Macaroni

Richard McCabe

Character: Sir James Hare

Calvin A. Dean

Character: Devonshire House Servant (as Calvin Dean)

Hannah Stokely

Character: Devonshire House Maid

Andrew Armour

Character: Burleigh

Emily Jewell

Character: Nanny

Bruce Mackinnon

Character: Sir Peter Teazle

Georgia King

Character: Lady Teazle

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

Kate Burdette

Character: Lady Harriet

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 (voice)