Young Hollywood isn't quite so young anymore. This weekend, Ansel Elgort turns 21, joining the ranks of several other celebrities who reach the milestone this year. Justin Bieber will continue his 21st birthday festivities later this month with his Comedy Central Roast, and after growing up on screen for more than a decade, Dakota Fanning celebrated the big 2-1 earlier this year. Ahead of Ansel's birthday, take a look at some of the famous actors and musicians who turn 21 in 2015, and then check out the hotties turning 30 this year and the best dressed stars under 21!
After so many years of watching Dakota Fanning on the big screen, it's hard to believe the actress only recently turned 21 on Feb. 23.
Justin Bieber embraced the big 2-1 in a big way on March 1, and the celebration will continue with his upcoming Comedy Central Roast.
The Lovely Bones and The Grand Budapest Hotel actress Saoirse Ronan will turn 21 on April 12.
After filming Boyhood from age 7 though 19, actor Ellar Coltrane will turn 21 on Aug. 27.
Vampire Academy's Zoey Deutch will celebrate the big 2-1 later this year on Nov. 10.
On April 14, Skyler Samuels from American Horror Story and The DUFF will turn 21.