When she first auditioned for Britain's Got Talent, the 48-year-old captured the public's imagination with her powerful voice and her down-to-earth quirky attitude.
And back then she famously told hosts Ant and Dec that she had "never been kissed".
Of course, with her global music career now a reality and with fans all around the world, Susan's love life is less of a priority for the star, who says she doesn't have time for romance anymore.
"I've had offers of dates," she has revealed. "But I'm far too busy! I've got my living to do now. I don't mind being friendly, but no marriage plans as yet!"
Susan's heart-warming success story is all the more poignant considering her childhood.
The West Lothian-born singer - whose fans include Demi Moore - has opened up about her youth in a documentary airing in December, revealing she was bullied as a child.
"They used to knock me about a bit and try and make me cry," Susan recalled.
"There's nothing worse than another person having power over you by bullying you and you not knowing how to get rid of that."
"I didn't make friends very easily. I did try to speak to people but they made fun of me," she said.
Now though, the former church volunteer is enjoying the ride, from being greeted by thousands of people as she arrived in LA, to chatting to Oprah, and staying in the same Hollywood hotel that Frank Sinatra "used to take his women back" to.
"I dipped my toes in the same pool Grace Kelly has been in," exclaims Susan. "This is a world I'd never seen before and never dreamed I would get to see."
ITV's The Susan Boyle Story – charting her incredible rise to fame – airs on December 13.