The 'Judas' singer ranked top on Forbes's list of the 100 most powerful celebrities, which takes into account a celebrity's income, social media and web presence, and the amount of press and TV coverage they receive.
GaGa, who earned $90 million (£56m) over the past 12 months, topped the list due to her extensive social media coverage, which includes 32 million Facebook fans and more than 10 million Twitter followers.
Last year's winner Oprah Winfrey fell to second place in 2011. Despite earning $290 million (£180m) over the past year, she notably ended her longrunning talk show Oprah earlier this week.
Canadian pop singer Justin Bieber took third place with his $53 million (£33m) earnings and extensive YouTube and Twitter presence.The remainder of the top ten in order consists of U2, Elton John, Tiger Woods, Taylor Swift, Bon Jovi, Simon Cowell and LeBron James.
Other notable changes include Leonardo DiCaprio's jump from 71 to 15 following the release of two highly successful films over the past year, and Britney Spears somehow managing to drop off the list entirely.
In previous years, the likes of Angelina Jolie, Tom Cruise and Mel Gibson have all been named the most powerful celebrities in the world, while Winfrey herself has won the title four times in the past.
