- Demi Lovato
- United States ()
Demi Lovato (USA, b. 20 August 1992) was 19 years 9 months 5 days old when they began filming the second season of The X Factor USA alongside Simon Cowell, L.A. Reid and Britney Spears on 24 May 2012. Lovato, who topped the US albums chart with "Here We Go Again" in 2009 and has enjoyed more recent success with the singles “Skyscraper” and “Give Your Heart a Break”, mentored the Young Adults category but failed to reach the final with any of the four acts they mentored.
The youngest winning X Factor judge is Charice (Philippines, b. Charmaine Pempengco, 10 May 1992), who was 20 years 5 months 5 days old when she mentored KZ Tandingan (Philippines, b. Kristine Tandingan) – two months her senior – to victory in the first season of The X Factor Philippines on 7 October 2012. Charice began filming the show’s live auditions six days after her 20th birthday, thus missing out on becoming The X Factor’s youngest judge by a matter of weeks.