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) more..., 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 (voice))

Jeffrey Hatcher (Screenplay), Anders Thomas Jensen (Screenplay), Michael Kuhn (Producer), Gabrielle Tana (Producer), Rachel Portman (Original Music Composer), Gyula Pados (Director of Photography), Masahiro Hirakubo (Editor) more..., Carolyn Marks Blackwood (Executive Producer), David M. Thompson (Executive Producer), Saul Dibb (Screenplay), Amanda Foreman (Novel), Michael Carlin (Production Design), Karen Wakefield (Art Direction), Rebecca Alleway (Set Decoration), Michael O'Connor (Costume Design), Fran Needham (Hairstylist), Corinne Bossu (Makeup Artist), Louise Fisher (Makeup Artist), Tapio Salmi (Makeup Artist), Rachael Speke (Makeup Artist), Stephanie Hovette (Wigmaker), James Collins (Assistant Art Director), Muffin Green (Property Master), Andrea King (Foley), Catherine Hodgson (Supervising Sound Editor), Roberto Cappannelli (Sound Re-Recording Mixer), Paul Hamblin (Sound Re-Recording Mixer), Simon Allmark (Visual Effects Editor), Ed Cross (Visual Effects Editor), Fay McConkey (Visual Effects Producer), Becky Roberts (Visual Effects Producer), Adam Gascoyne (Visual Effects Supervisor), Charlie Noble (Visual Effects Supervisor), John Colley (Gaffer), Vince Madden (Rigging Gaffer), Gerry Vasbenter (Camera Operator), Rodrigo Gutierrez (Additional Camera), Peter Mountain (Still Photographer), Marcus Alexander (Digital Intermediate), Jonathan Dixon (Digital Intermediate) and others.