The girls will be performing their brand new single 'Shout Out To My Ex' from their upcoming album.
It'll be the first performance of the track with the song released straight after the show.
Little Mix tweeted tonight: "We’re releasing #ShoutOutToMyEx next Sunday 16.10.16 after our FIRST EVER live performance of it on @TheXFactor!!💃❌ CAN’T WAIT! the girls x"
Little Mix will be the second X Factor champs to return to the show this year.
Tonight's first results show will see James Arthur back to perform his new Number 1 single Say You Won’t Let Go.
And it's also expected that last year's champ Louisa Johnson will return to promote her new album too.
This year the X Factor's results show guests also have an extra job.
Each Sunday, after the gut-wrenching eliminations, host Dermot O’Leary will be joined by the evening's perform who will spin the jukebox wheel to reveal to the remaining contestants and the viewers at home the following week’s theme.
Themes up for grabs include Oscars, Boy Band vs Girl Band, Disco, Motown, 80’s, Divas and - one we're VERY looking forward to - Louis Loves (the Louis Walsh collection).
The X Factor airs live at 8PM Saturday and Sunday night on ITV.