The Roar star has just hit 46.5 million followers, making her the most popular on the social network a position Bieber enjoyed for nine months.
The reason behind Katys soaring popularity? It's being attributed to the buzz surrounding her new album, Prism.
Katy should not rest on her laurels, though Beliebers are working furiously to close the gap. At last check, Bieber was just a few thousand behind the pop princess. Lady Gagas Little Monsters, however, have work to do the star is currently at just over 40.4 million followers.
Aside from a certain President Obama, who boasts just over 39 million followers, Twitters top five is dominated by musicians Taylor Swift edging into fifth place with her 36 million followers.