2013–2017: Early roles and Stranger Things In 2013, Brown made her acting debut as a guest star in the
ABC fantasy drama series
Once Upon a Time in Wonderland, a spin-off of
Once Upon a Time, portraying the role of
Young Alice. In 2014, she had a starring role in the
BBC America paranormal drama-thriller series
Intruders as Madison O'Donnell. She made guest appearances in the
CBS police procedural drama
NCIS, the ABC sitcom
Modern Family and the ABC medical drama series ''
Grey's Anatomy''. In 2016, she auditioned for
Lady Lyanna Mormont on
Game of Thrones but didn't get the role. Then, Brown was cast to play
Eleven in the
Netflix science fiction horror series
Stranger Things. She received critical praise for her performance and she was nominated for the
Screen Actors Guild Award for Outstanding Performance by a Female Actor in a Drama Series and the
Primetime Emmy Award for
Outstanding Supporting Actress in a Drama Series. She then won the
Screen Actors Guild Award for
Outstanding Performance by an Ensemble in a Drama Series with her co-stars and won the 43rd
Saturn Award for Best Performance by a Younger Actor in a Television Series. She reprised the role through to the series'
fifth and final season in 2025. In November 2016, Brown starred in the music video for
Sigma and
Birdy's single "
Find Me". Since November 2016, she has appeared in commercial advertisements for investment and financial service company
Citigroup. In January 2017, she made her modelling debut in
Calvin Klein's "By Appointment" campaign. The following month, she was signed to the agency
IMG Models. Brown appeared in the advertisement campaign of the Italian brand
Moncler in the summer of 2018. Brown has also made appearances on the cover of
Vogue.
2018–present Brown was chosen to voice in the
Darren Aronofsky-produced virtual reality experience
Spheres: Songs of Spacetime. In 2018, she was named one of the 100 most influential people in the world by
Time, becoming the youngest person to be included in the list. That year, she became the youngest person ever to be appointed a
UNICEF Goodwill Ambassador.
EA Games announced that Brown collaborated with
The Sims 4 programmers to feature in the Sims 4 Positivity Challenge. In 2018,
The Hollywood Reporter ranked Brown as amongst Hollywood's top thirty stars under age eighteen. Brown made her feature film debut in 2019 in
Godzilla: King of the Monsters, the sequel to the 2014 film
Godzilla. She reprised her role in the next sequel,
Godzilla vs. Kong (2021). She became the ambassador of
UEFA's Together #WePlayStrong campaign. In 2019, Brown launched
Florence by Mills, her own
beauty product line. It is available at UK pharmacy
Boots,
Walmart in the United States and
Shoppers Drug Mart in Canada. In 2020, Brown
starred in and produced the
film adaptation of
The Enola Holmes Mysteries, and later reprised the role in the 2022 sequel,
Enola Holmes 2. According to
Variety, she earned $10 million for the role, emerging as one of the year's highest paid actresses in Hollywood. That year, she was also made an ambassador of the fashion brand
Louis Vuitton. Brown released her debut novel,
Nineteen Steps, based on her own family history, in September 2023. The novel is described as an "epic story of love, loss and secrets". In 2024, Brown starred in and executive produced the fantasy film
Damsel for
Netflix, directed by Spanish filmmaker
Juan Carlos Fresnadillo based on a screenplay by
Dan Mazeau. In 2025, she starred in the
Russo brothers's
The Electric State, an adaptation of
Simon Stålenhag's graphic novel of the same name. In July 2025, Brown and
Gabriel LaBelle were set to star in the
Netflix romantic comedy film
Just Picture It. In 2026, she will reprise her role in
Enola Holmes 3. ==Collaboration and business ventures==