In February, she was behind actor Vin Diesel, actress Megan Fox and the US leader - but has now gone past all of them. According to Famecount, only five others, none of them living, have more Facebook fans than Lady Gaga. They are the late Michael Jackson, Texas Hold 'em Poke, the Family Guy TV show, the game Mafia Wars and the Facebook site itself.
"Achieving 10m fans is a key milestone for both Lady Gaga, and for social media in general. It is testament to the incredible reach of Facebook, and to the phenomenon of Lady Gaga," Sky News quoted Jamie Gavin from Famecount as saying.