Rihanna to guest judge on The X Factor

The names keep getting bigger for The X Factor! TMZ reports that Simon Cowell has snagged another megastar to guest judge on the show: Rihanna!

She will be helping L.A. Reid pick his roster.

Rihanna joins Mariah Carey who has also been tapped as a guest judge.

I'm so excited! X Factor premieres on September 21 on FOX.

Via TMZ