The former Disney star was stunned to learn she was a direct descendant of the ancient king on the US version of ‘Who Do You Think You Are?’
She even visited the site of his burial at Dunfermline Abbey during a trip to Scotland.
The 30-year-old singer said: “I’ve gone my whole life never hearing of this man, now I find he’s my 21-times great grandfather and also such a huge important part of history and such a brave man.”
Genealogist Nick Barratt, who broke the news to the actress, told her: “If this was the 13th century you would be a princess. I feel I should bow. You’re a royal.”
It’s not the first time an American actress has been revealed as a direct descendant of Scotland’s most famous king.
A new biography of Meghan Markle, the Duchess of Sussex, found it was possible to trace a direct line through 25 generations to Robert the Bruce.
The link to Bruce, who famously led a Scots army to victory against the English at the battle of Bannockburn, was revealed by royal biographer Andrew Morton .