Bieber took home seven awards at the Las Vegas ceremony, including top new artist, top pop album and fan favorite. Eminem, who did not attend, won six awards including top artist -- the top honor -- and top male artist.
"I'm 17 and I want to thank God because, you know, he's blessed me so much," Bieber said while accepting the new artist award. "Every day is crazy because I see so many people and I get to make so many people smile. . . . It's crazy that I'm surrounded by so many amazing people." He also thanked his mom and his fans.
The show, hosted by "The Hangover 2" star Ken Jeong, was packed with performances: scantily clad Rihanna, who opened the show with her hit "S&M" and was joined by Britney Spears, a piano-levitating Cee Lo Green, a much-bleeped Lil Wayne with Mary J. Blige, and Neil Diamond, who led an audience sing-along. Rihanna won for radio artist of the year and top female artist.
Taylor Swift, whose "Speak Now" won top country album, was named top country artist and top Billboard 200 artist. She told the audience: "You've just given me another reason to be completely in love with you."
Lady Gaga was named top pop artist and top dance/electronic artist, while The Black Eyed Peas won for top duo/group. Katy Perry won as top hot 100 artist. Usher became top R&B artist, and U2 was named top touring artist.
Beyoncé, 29, received a special Millennium Award for her career achievements and Neil Diamond took home the Icon Award.