The former Hollyoaks star will play Doreah in the adaptation of author George R. R. Martin's A Song of Ice and Fire novels.
Speaking to View London, she described her character as an "ex-courtesan [turned] handmaiden [but] actually still kind of working as a courtesan".
"It's so exciting to be part of such a huge project," she added. "It's incredible. It's amazing, so watch it."
She also described the sets for the nine-part fantasy drama as "out of this world".
Game of Thrones will launch in the US on April 17 on HBO. The show will air in April on Sky Atlantic in the UK.