If Hollywood is like a highschool, then these Hollywood mega-stars listed would probably have been deemed as the "late-bloomers". Here are the top 10 celebrities who started their careers early and grew up to become major knockouts in their own right:

Justin Timberlake

Now that this former boybander has since ditched his blonde curly locks, he looks even better than ever. His 2006 record "FutureSex/LoveSounds" helped seal his staying power in the music industry, which led to major roles in movies like The Social Network and In Time.

Scarlett Johansson

This modern Hollywood sex symbol started her career in 1994 when she was just 10. Small roles in straight to VHS movies soon escalated to films like Girl with a Pearl Earring and Lost in Translation.

Daniel Radcliffe

The boy wizard has certainly come into his own as a looker. Daniel Radcliffe's Harry Potter days might be behind him, but that's not stopping this talented actor from singing, acting, dancing, charity work, modeling, small screen, big screen and Broadway.

Emma Watson

Who can forget Hermione Granger from the Harry Potter franchise? Emma held her own in all eight Harry Potter movies before branching out from the silver screen and into the world of modeling, securing her place as one of Hollywood’s current leading ladies.

Natalie Portman

Portman began her career as the adorable Mathilda from the cult classic Leon the Professional. Her first huge commercial success was at age 18, when she played Padme Amidala in the Star Wars prequel trilogy. Since then, Natalie has gone on to wow audiences in several commercially successful movies including Black Swan, Thor and Thor 2: The Dark World.

Jennifer Lawrence

Currently one of the hottest actresses in Hollywod, Lawrence started her career on TV on The Bill Engvall Show. Her role in Winter’s Bone earned her an Oscar nomination. She eventually nabbed the statue for Best Actress for Silver Linings Playbook.

Josh Hutcherson

Hutcherson began his acting career in 2002, but only came to the attention of audiences in 2007 after starring in Bridge to Terabithia. That adorable performance earned him several awards for his performance. You can look forward to more good things from this actor in the massively successful Hunger Games franchise.

Jessica Alba

Voted multiple times as the sexiest woman in the business, Jessica was just eleven when she landed the role of Jessica in the Secret Life of Alex Mack. From there, she went on to star in sci-fi show Dark Angel and super hero movie The Fantastic Four. And who can forget her jaw-dropping scene in Sin City? And to think she achieved all that while enforcing a strict no-nudity clause in her contracts.

Leonardo DiCaprio

Young Leonardo started out on shows like Parenthood and Growing Pains. His breakthrough role in Titanic has propelled him to become one of Hollywood’s leading males with five Oscar nominations under his belt.