All 12 finalists, mentored by Gary Barlow, Louis Walsh, Nicole Scherzinger and Sharon Osbourne, will perform classic tracks from the decade that gave the pop world Madonna, Whitney Houston and Bon Jovi.
The live shows will also debut a new 'Flash Voting' twist, which is intended to shake up the elimination process.
The X Factor live shows start on Saturday, October 12 at 8pm on ITV. The first episode is a bumper two hours and 15 minutes.
BBC One's rival Saturday night series Strictly Come Dancing will overlap with The X Factor for 30 minutes.
The X Factor Final 12 acts will be revealed at the end of this weekend's (October 5-6) Judges' Houses episodes.