rihannahair230.jpgSimon Cowell continues to add excitement to his hit UK show X Factor with the addition of Rihanna, according to The Sun.

The 23-year-old "What's My Name?" singer will appear on the talent show as a guest judge. The UK site reports Cowell is a huge fan of Chris Brown's ex and will continue to feature more guest panelists throughout the season.

Audiences won't be seeing much of Cowell on the UK version because the former American Idol judge will be spending most of his time filming the US version. However, the 50-year-old judge will reportedly make it back in time for the UK's finals.

During last year's X Factor season, Cowell welcomed numerous guest judges including Geri Halliwell and former Pussycat Dolls' lead singer Nicole Scherzinger.

Find out which superstars are reportedly attached to the US version ... after the jump.