Leona Lewis, who won the show in 2006 and remains one of its most successful ever contestants, will join the new version as one of a handful of judging advisors to Cowell and fellow judge Nicole Scherzinger.
Who is Leona Lewis and when did she win The X Factor?
Leona emerged victorious in only the third series of The X Factor, beating Ray Quinn in the final.
She went on to score a number of big hits, including winner’s song Moment Like This, international hit Bleeding Love and Better In Time, while her first two albums (Spirit and Echo) both made it to the top spot of the UK albums chart.
In more recent years, Lewis has appeared on stage and screen, making her film debut in 2014 romantic comedy musical Walking on Sunshine, and making her first appearance on Broadway playing Grizabella in a 2016 revival of Cats.
She was one of the former contestants originally earmarked to appear on the now scrapped The X Factor: All Stars series that was set to air this month, and so it seems an X Factor return has been on the cards for a while.
The X Factor: The Band begins at 8:30pm tonight on ITV