The singer has reached almost 62 million fans on the social networking site, taking the lead over the rapper who became the first star to hit 60 million likes in July this year.
Rihanna's total currently stands at 61,664,389 fans on the site, compared to Eminem's 61,213,267 as of today (October 9).
Meanwhile, it was previously reported that Lady GaGa has become the most followed person on Twitter after accumulating 30 million since joining in March 2008.
GaGa places ahead of Justin Bieber and Katy Perry, while Rihanna is currently fourth with 26.1 million followers.
Rihanna is currently number one on the UK singles chart with 'Diamonds', which beat One Direction's 'Live While We're Young' after a close chart battle.
Listen to 'Diamonds' below: