JLS, who finished second on the 2008 series, will return on Sunday (October 21) to perform their new single 'Hottest Girl in the World'.
The band mentored the acts at this year's Boot Camp and collaborated with One Direction and the X Factor finalists of 2011 on charity track 'Wishing on a Star'.
Labrinth, meanwhile, is expected to play 'Beneath Your Beautiful', on which Sandé is a featured artist.
It was announced on last Sunday's Xtra Factor that the remaining 11 contestants will be tackling 'Club Classics' this week.
The previous series had a similar 'Dancefloor Fillers' theme, which saw eventual winners Little Mix perform Rihanna's 'Don't Stop the Music' and runner-up Marcus Collins cover 'Reet Petite'.
It was reported this week that Beyoncé has been approached to duet with Ella Henderson should she make it to the X Factor final.
The X Factor continues Saturday (October 20) at 8.20pm on ITV1.
Digital Spy breakfast show - watch Anna Williamson discuss the day's biggest stories including Girls Aloud, X Factor and The Great British Bake Off: