Brown was born on 19 February 2004 in Marbella, Spain to British parents Kelly and Robert Brown as the third children out of four.
In 2013,She made her acting debut as a guest star in the ABC fantasy drama series Once 'Upon a Time in Wonderland' and played the role of Young Alice.
She has become popular for playing Eleven in the Netflix science fiction horror series 'Stranger Things' and Enola in 'Enola Holmes'
She is currently working for Enola Holmes 2 which is the mystery film of the adult series.
She was nominated for Primetime Emmy Awards and won one Screen Actors Guild Award.