According to BET.com Minaj moved ahead on January 4 and at last count had a total of 8,287,306 followers to Marshall's paltry 8,265,540.
She still has a long way to go before becoming the most popular musician overall, currently languishing behind eight others. Lady Gaga is Twitter's most followed artist with nearly 18m followers.
When asked by a fan if she knew about her new status, Nicki replied "Do now! ;)".
Eminem is yet to comment but then he hasn't even tweeted in a month anyway.