The Chained To The Rhythm hitmaker has reached the milestone number of fans on the social media site, followed by Justin Bieber, who has 96.7 million followers, while Barack Obama (90.8 million), Taylor Swift (85.1 million) and Rihanna (74.1 million) placed third, fourth and fifth respectively.
To celebrate Katy’s achievement, Twitter posted a video on their own official account of some of Katy’s greatest tweets over the years.
They captioned it: “Today, we #WITNESS history. Congratulations @katyperry, the first to reach 100 million followers! #LoveKaty.”
Meanwhile, 32-year-old Katy – who joined Twitter in February 2009 – reckons she is so popular on Twitter because she writes her own tweets.
She said: “I would say 90 percent of my Tweets, I’ve just made them up and you can tell because many of them are misspelled and full of typos.
“But the other five per cent is work-related or it’s just to keep people in the know about where I’m playing or if I’m doing a show and I always get really confused.”