Isabella May Ramsey (born September 2003) is an English actor. They are known for their breakthrough role as young noblewoman Lyanna Mormont in the HBO fantasy television series Game of Thrones (2016–2019) and Ellie in the HBO post-apocalyptic drama series The Last of Us (2023–present). They received nominations for a Primetime Emmy Award and a Golden Globe Award for the latter.

Ramsey played Mildred Hubble in the 2017 CBBC series The Worst Witch, voiced the title role in the Netflix animated series Hilda (2018–2023), and starred in the 2022 historical comedy film Catherine Called Birdy. The latter earned them a nomination for the Critics' Choice Movie Award for Best Young Performer.