The 49-year-old reality television show star will perform her version of Lou Reed's Perfect Day for Charles and his wife Camilla at the Daily Mirror's Pride of Britain Awards on Monday.
Boyle said Tuesday it is a "real privilege" to be able to sing for the royals.
The singer, who shot to international fame after her stint on "Britain's Got Talent," performed during a ceremony for the pope when he visited the U.K. in September.
