Boyle, 49, is set to appear on the show in an upcoming festive episode.
Rumors are also rampant that the songs Boyle will perform on the show will be available for download before the holidays.
A source said to UK newspaper Daily Record: 'Susan's appearance will be great fun for all fans of the series.'
In other Boyle news, SuBo is set to release her next album, "The Gift" on November 8.
She has been working hard on the album and is said to be really proud of the finished product.