Billboard has released their annual list of the hottest musical acts in the world under the age of 21, and of course, Justin Bieber, is on top!

According to Billboard, Bieber “remains more powerful in the pop universe than ever” having released two No. 1 albums in the last year – holiday set “Under the Mistletoe” and his latest pop album, “Believe”.

This is the second year in a row that the young Canadian supertar topped the annual “21 Under 21” list despite the popularity break-out of British boyband One Direction in the last 12 months.

The X Factor USA judge, Demi Lovato, is running in third followed by 2011 American Idol Scotty McCreery (#4), rapper Mac Miller (#5) and the Bieber girlfriend Selena Lopez (#6). Complete list below…

Billboard’s “21 Under 21″ for 2012:

1. Justin Bieber
2. One Direction
3. Demi Lovato
4. Scotty McCreery
5. Mac Miller
6. Selena Gomez
7. Porter Robinson
8. Cher Lloyd
9. Earl Sweatshirt
10. Nick Jonas
11. Jackie Evancho
12. Cody Simpson
13. Mindless Behavior
14. Megan & Liz
15. IU
16. Bridgit Mendler
17. 3BallMTY
18. Miley Cyrus
19. Madeon
20. Ross Lynch
21. Victoria Justice