Ronan hosted the 2 December 2017 episode of "Saturday Night Live", in which one of her sketches was criticised in the media for stereotypical portrayal of Irish people, and featured in the music video for Ed Sheeran's song "Galway Girl". The following year, she starred in an adaptation of Anton Chekhov's play "The Seagull", in which she played Nina, an aspiring actress. In a mixed review of the film, Michael O'Sullivan of "The Washington Post" praised Ronan's performance, writing that she "makes for an incandescent Nina, especially in her loopy final-act speech". She then starred as Mary Stuart in the period drama "Mary Queen of Scots", co-starring Margot Robbie as Elizabeth I of England. To maintain the distance between their characters, Ronan and Robbie did not interact with one another until filming their climactic encounter. Critic Todd McCarthy praised both actresses' performances and credited Ronan for "carr the film with fiercely individualistic spirit".