The 'Baby' singer performed two songs on the FOX talent show - one with Stevie Wonder for a rendition of 'The Christmas Song' before taking to the stage with former contest Drew Ryniewicz to sing the classic 'Santa Claus Is Coming To Town'.
Before the show, the 'Never Say Never' hitmaker tweeted his excitement at performing at the final.
He wrote: "Next week we got the FINALE of X FACTOR in the US and Im going HARD! There will be some big surprises (sic)."
The show was won by Simon Cowell's protege Melanie Amaro, who was crowned the first winner of the US 'X Factor'.
The 19-year-old Sunrise, Florida, native beat runner-up Josh Krajcik, 30, to take home the $5 million contract with Simon's record label SyCo and a role in a Pepsi Superbowl TV commercial and the media mogul revealed he was happy he changed his mind about sending her home at the Judges' Houses stage.