Rebecca wore a purple dress by fashion designer Oscar De La Renta as she walked down the red carpet at the Tower of London.
The top half, which was a floaty chiffon material, was complimented well by the sequin floor-length skirt.
The 28-year-old teamed her striking outfit with a pair of sparkly black heels. Rebecca went all out on the beauty front too, rocking a matching pout and big curly hair.
Taking to Instagram. she said: "Thank you @thedresserldn for my Oscar De La Renta outfit for the Game of Thrones premiere. So exciting here at the Tower of London but a little creepy.'
This week, Rebecca announced a 20-date UK tour kicking off next year. The singer will perform across the UK in January and February, kicking off on 22 January in Oxford, before wrapping up in Southampton on 18 February.
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