Michael Buble, Robbie Williams and George Michael will duet with the X Factor finalists over the weekend.
Stacey, Joe and Olly will compete to be this year's winner with a bit of help from the stars.
Stacey will sing with Michael Buble, Joe will partner George Michael, while Olly will duet with Robbie Williams who's been on the show before.
Almost 17 million people have been watching over the last few months and this weekend it's decision time.
Chart success
Whoever wins out of Stacey, Olly and Joe has a good chance of becoming a massive music star.
Previous winners have enjoyed huge success in the charts.
Last year's star Alexandra Burke has had two number one singles and a number one album.
And runners up JLS have also topped the charts with two singles and an album.
Source:bbc.co.uk/