She's Only 15, but Millie Bobby Brown Is Already Cooler Than Most of Us

Despite all that poise, Millie is crazy young: she was born on Feb. 19, 2004. She may act very mature, but she sometimes reminds us of her indomitable youth when she does things like make hilariously silly YouTube videos with Stranger Things costar Noah Schnapp.

As you've gathered from her accent in TV interviews and speeches, Millie is a Brit. She hails from the UK, though she was born in Spain. She also has three siblings: a brother named Charlie and two sisters named Paige and Ava.

Before Stranger Things, Millie had guest roles on Modern Family, Grey's Anatomy, and the Once Upon a Time spinoff, Once Upon a Time in Wonderland (she played young Alice!). She also starred in a British series called Intruders before hitting it big on Netflix.

In 2019, Millie starred in the blockbuster Godzilla: King of the Monsters. She'll soon appear in the sequel, Godzilla vs. Kong, as well as a film adaption of Nancy Springer's book series Enola Holmes and a book-to-movie rendering of Ali Benjamin's The Thing About Jellyfish.

Millie became UNICEF's youngest-ever Goodwill Ambassador in 2018 and has used her role to encourage world leaders to invest more in the well-being of children. In 2019, she delivered a powerful speech at UNICEF's summit for Universal Children's Day and spoke about various topics, including bullying and climate change. Millie has also used her platform to speak against gun violence.

As if being an amazing actor, activist, and producer isn't enough, Millie also has her own beauty line, Florence by Mills. The brand includes makeup and skincare products, including lip oils, facial scrubs, and under-eye creams.