Isabella Sermon was born in London, UK. Isabella was first discovered aged 10 years old whilst at school. She won the role of Maisie Lockwood in Jurassic World: Fallen Kingdom in 2016 after a casting process for the film involving over 3,000 young actors in the UK and US. Isabella returned to the role of Maisie Lockwood for Jurassic World: Dominion which was the first production to recommence filming during the pandemic in 2020, which then premiered in 2022. Isabella subsequently worked with Rosamund Pike on "People Who Knew Me", an audio drama, for Merman/Mermaid Productions and BBC Sounds in 2023.