21 Under 21 List For 2013 Features 1D & More!

Billboard's have just released their 2013 list of the great artists under the age of 21, "21 Under 21"!

One Direction, Justin Bieber, Ariana Grande, Austin Mahone, Emblem3, Bridit Mendler, Mindless Behavior, Matty B., Fifth Harmony and more made this year's 21 Under 21 stars!

The obvious #1 on the list was the unstoppable boy band One Direction who have taken the world by storm since their formation on The X Factor three years ago.

Just two years ago, the boys were toward the bottom of the list at #19! Last year, they leaped to the second place spot. This year, One Direction reign, but next year they'll be disqualified because of their ages!

The former king, Justin Bieber, fell from the #1 spot for the last two years in a row to the #2 spot. Still, he seems to be hanging in strong!

Other repeat winners include Good Luck Charlie star Bridgit Mendler, who jumped from #16 last year to #13 this year thanks to the success of her show.

Boy band Mindless Behavior fell from the #13 spot last near to #18 this year, but we don't think we've seen the last of the boys! They'll all be under 21 for a few more years, and we expect them to keep appearing on subsequent lists!

Which 21 Under 21 celebs are your favorites?