A decade after she impressed judges with her rendition of the musical standard, the 58-year-old will return to perform for Simon Cowell, Alesha Dixon, Amanda Holden and David Walliams.
Following a lengthy standing ovation, Cowell will take to the stage at the London Palladium to embrace Boyle, telling her: “Still got the magic, Susan. Haven’t you? Thank you for coming.”
The episode, the second of this year’s contest, will also see Boyle reunited with presenting partners Ant and Dec, who will pull her in for a hug after she leaves the stage.
“Ten years older. It’s been 10 years, hasn’t it?” Ant McPartlin will ask her.
“And you two haven’t changed a bit,” she will respond before embracing the pair.
“You can come again,” Declan Donnelly will then quip.
The Scottish singer’s debut album, I Dreamed A Dream, was released in November 2009 after she narrowly missed out on first place to Diversity during the third series of the ITV show.
The record became the UK’s best-selling debut of the time, beating a previous record held by Leona Lewis’s Spirit.
But the melodramatic mood will be suddenly cut short with the entrance of a Japanese hopeful performing under the name Gonzo.
Holding a tambourine and dressed in tight-fitting lycra, he will prove the judges’ preconceptions wrong with a skilful if comedic performance of Livin La Vida Loca by Ricky Martin.
Asked why he had decided to compete in the show, Gonzo will reply: “I saw on YouTube in Japan Susan Boyle. Oh yes. I recommend Susan Boyle’s energies into my heart. Very right, yes.”
Wowed by his performance, Cowell will tell Gonzo: “I knew the minute you walked out that you were going to be amazing.”
Britain’s Got Talent continues on ITV at 8pm.