The Barbados-born popstar, who caused controversy with her raunchy performance on last year's X Factor final, will top the bill on next Sunday's (November 27) ITV1 showdown.
Meanwhile, Ferguson makes her first return to the X Factor stage since finishing runner-up in the 2010 series. She is expected to perform 'Nothing's Real But Love', the lead track from her debut album Heaven.
Lady GaGa appeared on yesterday's (November 13) results show and came out to comfort eliminated contestant Kitty Brucknell on spinoff show The Xtra Factor.
Six contestants remain on The X Factor with the chance of winning a Syco record contract and to become Christmas number one.
Amelia Lily is the new bookmakers' favourite after returning to the ITV1 show as a wildcard act on Saturday.