The X Factor is a British television music competition to find new singing talent. The fourth series was broadcast on ITV from 18 August 2007 and was won by Leon Jackson on 15 December 2007, with Rhydian Roberts finishing as the runner-up and Dannii Minogue emerging as the winning mentor. Dermot O'Leary presented for the first time, replacing Kate Thornton, who had been presenting the show since series 1 in 2004. Fearne Cotton replaced Ben Shephard as presenter on the spin-off show The Xtra Factor. The original judging panel consisted of Simon Cowell, Minogue, Sharon Osbourne and Brian Friedman. Friedman left the panel halfway through the first audition episode and was replaced by former judge Louis Walsh.

The X Factor is a British reality television music competition, created by Simon Cowell. Premiering on 4 September 2004, it was produced by Fremantle's British entertainment company, Thames, and Cowell's production company Syco Entertainment for ITV, as well as simulcast on Virgin Media One in Ireland. The programme ran for around 445 episodes across fifteen series, each one primarily broadcast late in the year, until its final episode in December 2018. The majority of episodes were presented by Dermot O'Leary, with some exceptions: the first three series were hosted by Kate Thornton; while Caroline Flack and Olly Murs hosted the show for the twelfth series.