The Queen of Pop recently snapped a picture of herself in costume as Emilia Clarke's character in the hit HBO fantasy drama and the stars of the show were shocked to discover she's a fan.
Speaking to BANG Showbiz at the 'Game of Thrones' Season 4 UK premiere last night (25.03.14), John Bradley - who plays loveable Samwell Tarly - said: "It's amazingly flattering. When a cultural icon adopts you and endorses you, in a funny kind of way, you know you've hit the nail on the head. It's very flattering."
Sansa Stark actress Sophie Turner also praised Madonna, 55.
She added: "I've been shown a lot of photos of that. It's pretty cool - the Queen of Pop dressing as the Mother of Dragons. It's pretty cool."
Sophie, 18, was left stunned in January when A-list stars Jennifer Lawrence and Aaron Paul cornered her at the Golden Globe Awards and gushed over 'Game of Thrones'.
Quizzed about her most exciting celebrity fan moments, she said: "The coolest was Jennifer Lawrence.
"I've heard that Eva Longoria said in an interview she fancied Jon Snow [Kit Harington], which is quite funny and surprising."
'Game of Thrones' Season 4 begins on Sky Atlantic Monday, April 7, at 2am - screening at the same time as it airs in the US - and will be shown again at 9pm.