"Huge global star" Boyle will join Michael Bublé and Katherine Jenkins at the 'The World Comes To Windsor' knees-up.
The party will also include performances by representatives from across the Commonwealth with dance, military pageantry and equestrian displays.
The show will be screened on ITV this summer with a source saying: "[Susan] is a great booking for such a prestigious event".
Thanks for that, 'Source'. Great insight.