The US singer, who is currently promoting her new album Born This Way, moved up four places to take the number one spot on Forbes’ celebrity power list.
The celebrity power list measures power by analysing entertainment-related earnings, media visibility and social media popularity; Lady Gaga, real name Stefani Germanotta beat the likes of Justin Bieber who made his debut at number three and Taylor Swift who entered the list at number seven.
Forbes rated the American singer-songwriter number one, estimating her earnings in the past 12 months as $90 million, but also noting her 32 million Facebook fans and 10 million Twitter followers.
"Lady Gaga beat Oprah this year because of her social media power. She can use Twitter and Facebook to work the "little monsters" into a frenzy that leads to record sales and media attention. She's the best example of how celebrities will need to manage their careers in the coming years," Forbes editor Dorothy Pomerantz said.
Oprah Winfrey - who next week ends "The Oprah Winfrey Show" syndicated TV chat show after 25 years - dropped one place from last year to number two; she earns an estimated $290 million.
Canadian pop star Justin Bieber was the youngest to make the list aged just 17, and debuted at number three earning $53 million from concerts and sales from his concert movie and documentary "Never Say Never."
U2 were placed at number four, earning $195 million and Elton John followed in fifth place earning $100 million.
Forbes said its earnings figures consist of pretax income between May 1, 2010, and May 1, 2011
Rounding out the top ten for 2011 was golfer Tiger Woods, earning $75 million, country singer Taylor Swift, rock band Bon Jovi, British music producer and "The X Factor" judge Simon Cowell and US basketball player LeBron James.
Other big newcomers include singer Katy Perry at number 12, British director and producer Christopher Nolan at number 47 and actress Natalie Portman at number 75. Britney Spears and Harry Potter actor Daniel Radcliffe move out of the list.
The full list can be viewed at the Forbes website
