The popstar will be returning to his X Factor contestant roots as he performs his new song 'Kiss Me' this weekend… before swapping back into presenter mode to announce which act is going home.
Olly found fame on the sixth series of X Factor in 2009 and went on to become a successful recording artist. His latest album, Never Been Better, was released last year.
He'll release a special edition of the album later this month, which features the track 'Kiss Me'. It's already been a top ten hit in the UK.
He'll be joined on Sunday night's results show by guest performer Nathan Sykes, formerly of The Wanted, who will sing his latest track 'Over and Over Again'.
On the Saturday night show, superstar Ed Sheeran and Rudimental will perform 'Lay It All On Me'.
Olly made headlines after last weekend's X Factor when he accidentally slipped up and announced Monica Michael had been eliminated following the judges' vote, after miscounting. The judges had actually sent the results to deadlock.
Monica was then eliminated leading some fans to accuse the show of being fixed. Olly, however, said it was a genuine mistake, saying: "I am still learning and hope that never happens again."