The Beatles musician will take to the stage for a special event at Buckingham Palace on June 4, held to celebrate the 60th anniversary of Elizabeth II coming to the throne.
Sir Tom Jones, Dame Shirley Bassey, Jessie J, JLS and Ed Sheeran are also believed to be part of the line-up.
The event is being partly organised by Take That star Gary Barlow, who has apparently spent a year trying to persuade McCartney to commit.
"He laid it on thick, telling him he was the only man for the job," a source told The Sun.
The Jubilee concert is to be part of four days of celebrations and will be broadcast on the BBC.
Barlow has confirmed on Twitter that more details of the Diamond Jubilee event will be announced on The One Show tonight (February 7) at 7pm.
> Queen marks 60 years on throne with Diamond Jubilee message of thanks