Keira Knightley

as Georgiana Cavendish, Duchess of Devonshire

Ralph Fiennes

as Duke of Devonshire

Charlotte Rampling

as Lady Spencer

Dominic Cooper

as Charles Grey

Hayley Atwell

as Bess Foster

Simon McBurney

as Charles Fox

Aidan McArdle

as Richard Brinsley Sheridan

John Shrapnel

as General Grey