In Game of Thrones Dormer is playing the role of Margaery Tyrell, starting in the second season. She was announced in the role on 23 June 2011 and was the first actor to be announced for the second season of the series. She enjoyed working on the show and found the large ensemble to be very well supported. She is a new starring cast member for the second season.
When asked if she thought Margaery was being insincere when she gave out food aid to the orphans and smallfolk of King's Landing in Season 3, Dormer said it was a mix of political pragmatism as well as legitimate concern for her subjects: "It doesn't mean she's insincere. People can be quite cruel, I find, about Margaery: 'Oh, she's another malicious, calculating character who's after the Throne.' But I don't think in regards with her attitude to the public and her attitude to Sansa – she's not disingenuous. I don't see the two as mutually exclusive, as modern politicians themselves would say. I think she has a heart. I think she can be very sincere. I just think she's a pragmatist. She's been brought up by the Queen of Thorns, Lady Olenna, being played by Diana Rigg [stay tuned!], to be a shrewd politician – to be the ideal First Lady, as it were.