Lady Gaga is the micro-blogging site's first user to amass that many followers. The milestone was hit on Saturday night
To say thank you, @ladygaga sent out a tweet to her fans on Sunday morning that said, "10MillionMonsters! I'm speechless, we did it! Its an illness how I love you. Leaving London smiling."
Gaga calls her fans "little monsters."
The pop star was the first living person to get 10 million likes on Facebook in July 2010, and on YouTube, Gaga was the first to reach 1 billion views in October 2010.
The top Twitter users are: