ITV has announced a star-studded lineup of guest performers for the season finale of "The X Factor," led by Elton John.
Also set to appear on the season-ending episode of the Simon Cowell-created show at London's Wembley Arena are boys band One Direction and Katy Perry.
John will perform a duet with X Factor U.K. judge Gary Barlow during the Dec. 15 show. They will debut "Face to Face" from Barlow’s new album "Since I Saw You Last."
John has in the past criticized music talent competitions on TV, including X Factor. A few years ago, for example, he said the show presented contestants like "products" rather than creatives. And this year, John said The Voice, which airs on the BBC in Britain, was producing "non-entities."
Perry will perform new single "Unconditionally," and former X Factor contestants One Direction will sing "Midnight Memories."
On the final Saturday episode of X Factor, also set to take place at the Wembley Arena, The Killers will play a medley of their hits, with Tom Odell also set to perform.
The X Factor U.K. has earlier this season also featured guest performances from the likes of Robin Thicke, Lady Gaga, Britney Spears and last year's winner, James Arthur.
Despite mixed ratings this year amid continued competition from BBC hit show Strictly Come Dancing, X Factor continues to draw millions of viewers each week in its 10th season. ITV recently struck a new three-year deal that will keep the show on the air.