The 47-year-old resident of West Lothian, Scotland, sang the song last week as she auditioned before awestruck judges and audience members.
Since then, the entire world has been watching -- and rewatching -- the dowdy woman with the unlikely, big voice.
Boyle now has some competition as the show advances. Shaheen Jafargholi, a 12-year-old who sang a Michael Jackson's "Who's Loving You" this week, wowed the judges with his ability.
However, she is still set to be the queen of the YouTube world, no matter the competition's outcome, and her following continues to grow.
Since the show's debut, a fan site has sprung up with the slogan "Never Judge a Book By Its Cover," as well as scores of social networking groups recognizing her as more than a phenomenon -- but rather, a bona fide star.