Lady GaGa was the most listened to artist on the internet in 2009.
Tracks from the star's 2008 album, The Fame, were played more than 18.5 million times on leading music site Last.fm.
She clocked up six million more plays than The Killers, who came second in the rundown.
British singer Lily Allen was named the third most popular artist, while the Prodigy were at number four.