McEwen studied History of Art at the University of Leeds and then trained at the Bristol Old Vic Theatre School.
[2] McEwen spent time with the Royal Shakespeare Company and won acclaim for her performances in Timon of Athens and Tamburlaine.
[3] McEwen appeared as Desdemona in Clint Dyer's production of Othello at the Royal National Theatre in London, a role The Evening Standard said she “knocked out of the park”.
She played Christopher Eccleston’s daughter in the Channel 4 miniseries Close to Me and alongside Eddie Marsan in the science fiction film Vesper.
[11] McEwen will appear in the Prime Video series Scarpetta as a younger version of the title character, a role she shares with Nicole Kidman.