The singer was a guest judge on the show back at the auditions and will be returning to perform her new single at the final.
It completes a rather dull list of performers for what's meant to be the climax of the series, with many guest stars having already appeared this year.
One Direction will be making their third appearance on this year's live shows, while it'll be the second time out for Rhianna, Rita Ora and Emeli Sande.
Fortunately there will be some new faces, although unsurprisingly they're also both closely linked to the show's team.
Britain’s Got Talent 2012 finalists Only Boys Aloud will be performing, ahead of the release of their debut album.
The Welsh choir group, made up of over 100 men and boys, finished in third place on the show this year and have since been signed to Simon Cowell’s Syco label.
Choir member said: Rhys Slade-Jones: “I have to pinch myself.
“We’ve got an album out, we’re doing the X Factor final and we’re touring next year."
Kylie Minogue will be singing after her appearance on Strictly last month, while US signer Kelly Clarkson will be back on the show.
However none of the stars will be singing alongside the contestants.
This year, for the second time, the remaining three finalists will be singing with their acts.
Jahmene and James will be dueting with Nicole Scherzinger, and Christopher will be singing with Gary Barlow.
It’s quite a let down, but then that seems par for the course this series.
The X Factor 2012 continues next weekend with the live final in Manchester.