'The X-Factor,' the U.K. version of 'American Idol,' is in for a dose of star power. For the reality show's upcoming season finale, the final four competitors will be collaborating with some of music's biggest acts, with Rihanna, will.i.am, Christina Aguilera and Robbie Williams set to perform alongside the contestants this Saturday night at 7PM on British channel ITV1.

During a press conference, the finalists revealed their duet partners. Show creator Simon Fuller said that his group One Direction will be singing with Williams, while Rebecca Ferguson excitedly shared that she would be going note for note with Xtina. Cher Lloyd, who became a viral sensation after performing a sexy rendition of Keri Hilson's 'Turn My Swag On,' will share the stage with the Black Eyed Peas frontman, while Matt Cardle will get a dose of Caribbean flavor from Rihanna.

Outside of the United States, 'X-Factor' has become one of the biggest reality competitions in history. The show, which originated in the U.K. in 2004, has made its way more than two-dozen countries, and has jump started the careers of past competitors Leona Lewis and Alexandra Burke. The show is expected to come Stateside for its first season in 2011.