Cheryl Cole, Nadine Coyle, Kimberley Walsh, Sarah Harding and Nicola Roberts have apparently agreed to reunite for the gig in November, the month of their tenth anniversary.
A Girls Aloud source told the Daily Star Sunday: "Being asked to perform at the Royal Variety Show is massive for the band.
"They performed in 2004 when they were at the height of their fame so it's fitting that they would return eight years later. It's the Variety Show's 100th anniversary and the lineup will be full of A-listers.
"It will be one of the Queen's final engagements of a year which will have seen her Diamond Jubilee and the Olympics. So it's a major scoop for the girls' comeback to be added to the bill."
The band's performance will be shown in an ITV documentary - 10 Years Of Girls Aloud - to be broadcast after the X Factor final in December.
The insider added: "The weeks leading up to the big night will be captured in the documentary, which was given the green light by producers last month.
"The programme will also look at the group's rise to fame, their domination of the charts and their solo careers. It will also have new interviews with all five members."
The Royal Variety Performance, which will see Queen Elizabeth II in the audience to cap her Diamond Jubilee year, will take place at the Royal Albert Hall on November 19.
Cheryl Cole teased in May that an announcement regarding Girls Aloud's anniversary plans would happen "very soon", but nothing was forthcoming at the time.
Watch the music video for Girls Aloud's 'Love Machine' below: