Rihanna was No. 2, followed by /*Katy Perry*/, /*Lady Gaga*/ and Lil Wayne. The list, announced Friday, takes into account album sales, charting singles, radio airplay and other factors.
Rounding out the list was Bruno Mars at No. 6, Nicki Minaj at No. 7, /*Taylor Swift*/ at No. 8, /*Justin Bieber*/ at No. 9 and Chris Brown at No. 10.
/*Adele*/'s album "21" was the best-selling of the year with 4.8 million sold. Following "21" on the list: Swift's "Speak Now," Gaga's "Born This Way," Jason Aldean's "My Kinda Party" and Susan Boyle's "The Gift."
Adele also had the most popular song with "Rolling in the Deep." LMFAO's "Party Rock Anthem" featuring Lauren Bennett and GoonRock was No. 2, Perry's "Firework" was No. 3, her "E.T." with Kanye West was No. 4 and Pitbull's "Give Me Everything" featuring Ne-Yo, Afrojack & Nayer was No. 5.
Adele was the top female artist. Lil Wayne was the top male.
The British soul singer also had iTunes' best-selling album and song, and she was named its top artist.
The Associated Press contributed to this report.