But who exactly will appear on the X Factor stage? And what songs will they be singing?
Here’s all you need to know…
Scarlett Lee will be singing with Robbie Williams and Leona Lewis
Song with Robbie Williams: Angels
Winner's Single with Leona Lewis: One More Sleep
Scarlett's individual Saturday night song: Your Song (Elton John)
Although we’ve seen judges perform with contestants over the years, it’s normally with an act in their own category (think how Nicole Scherzinger sang with Matt Terry, or Rita Ora with Louisa Johnson).
However, it was always going to be unlikely that Scarlett’s mentor, Simon Cowell, was going to offer to duet. So, looks like Robbie Williams has stepped in. (With all the acts in his Groups category already eliminated, he’s got to do something, right?)
Then, on Sunday's results show Scarlett will be joined on stage by Leona Lewis, performing her winner's single One More Sleep which will be released if she wins the competition.
Dalton Harris will be singing with Emeli Sandé and James Arthur
Song with Emeli Sandé: Beneath Your Beautiful
Winner's Single with James Arthur: Power of Love
Dalton's individual Saturday night song: A Song For You (Donna Hathaway)
The Jamaican finalist is joining forces with Emeli Sandé to give fans a version of Beneath Your Beautiful, a song Sandé originally performed with Labrinth. As X Factor fans will know, the pair belted out the single on the show in 2012, a well-received performance that may have helped the song reach number 1 in the UK charts.
Dalton will then be joined on Sunday by X Factor winner James Arthur, with the pair belting out Dalton's winner's single Power of Love.
Anthony Russell will be singing with Tom Walker and The Kaiser Chiefs
Song with Tom Walker: Leave a Light On
Winner's Single with The Kaiser Chiefs: I Predict a Riot
Anthony's individual Saturday night song: Let It Be (The Beatles)
Leave a Light On should be very familiar to viewers: Walker performed his hit single on the fifth live result show this series.
Meanwhile, The Kaiser Chiefs led by Ricky Wilson – who used to be a coach on fellow singing show The Voice – will join Anthony during Sunday's final for a winner's single collaboration – I Predict a Riot – in a bid to win the competition.
The X Factor is on 7.30pm Saturday and Sunday, ITV
