The 16-year-old beauty debuted her brunette tresses at the premiere of "The Boxtrolls" at Universal City Walk on Sunday.
The formerly-blonde actress paired her brown bob with an all-black ensemble from Oscar de la Renta.
Sporting a strapless, peplum, and bow tie-adorned top and floor-sweeping trousers, the red carpet look was a noticeably darker and more mature look than we're accustomed to seeing from the young starlet.
Despite her sophisticated outfit, Fanning managed to keep her look fresh and youthful by sporting natural eye makeup and a subtle nude lip.
Elle clearly isn't afraid to take fashion risks, and she has a distinct personal style.
"For my own style, I love vintage. 60's and 70's are my favorite," she recently told Seventeen. "I love baby doll dresses and the soft colors. I try to mix a little bit of modern into that — maybe I'll wear it with boots. At my school we wear a uniform, but we have one day a week we can wear whatever we want."
"I take a lot of risks. I like to stand out and look unique," she added.
What do you think of her darker 'do -- and more mature look? Sound off below.