Girls Aloud member has not been listed on the line-up but will be a surprise guest.
Cheryl Cole will sing for Queen Elizabeth at the Diamond Jubilee concert.
The 'Call My Name' singer has not been officially named on the line-up of the show on June 4 but reports say she has agreed to appear.
The 28-year-old star will perform live in front of a global audience for the first time in more than a year and Cheryl may perform a duet with organiser Gary Barlow.
She was due to perform a duet with the Take That member for 'Children In Need' in November last year, but it was cancelled when Cheryl got sick ill.
A show source told the Mirror: ''There are already huge names appearing on the bill but Cheryl is the cherry on top.
''She is one of the biggest stars in Britain and will ensure young people tune into the concert.''
The insider continued: ''She doesn't do many live appearances but when Gary asked her she couldn't turn him or the Queen down.
''She is promising a spectacular performance and I am sure the Princes will all be happy she is on the bill.''