The glamorous 34-year-old star donned the over-sized garment which boasted fake crocodile skin shoulder pads over a pair of skin-tight leather trousers.
The former Pussycat Doll posed with her two finalists Jahmene Douglas and James Arthur, who looked causal in jeans and polo shirts on the red carpet at Manchester Central Arena.
Tulisa Contostavlos braved the cold in a sleeveless satin dress and a pair of open toe ankle boots, before cosying up to fellow judge Louis Walsh, who kept warm in a turtle neck and a blazer.
Meanwhile, Gary Barlow posed for photographs with his final act Christopher Maloney, who Noel Gallagher recently pledged his support for.
Rita Ora, Rihanna and One Direction are a few of the acts set to perform during Saturday and Sunday night's final at Manchester Arena.
See pictures from The X Factor's live results show last weekend:
Copyright: Ken McKay/Thames/Rex Features