He appeared in Christopher Nolan's war film Dunkirk (2017) and won a Drama Desk Award in 2019 for his performance in the play The Ferryman.

[5] He secured a lead role in the BBC military drama The Last Post,[2] launched as part of the new season Autumn 2017 content on BBC1.

[2] He plays Peter, the son of the small boat captain who sailed to rescue British soldiers from the surrounded city Dunkirk.

[2] In 2018 Glynn-Carney was named as one of Screen International's Stars of Tomorrow, along with Naomi Ackie, Jessie Buckley, and Connor Swindells amongst others.

[9] In 2019 he starred as Henry "Hotspur" Percy in the David Michôd directed film The King[5] in a cast which included Robert Pattinson, Sean Harris, Timothée Chalamet and Lily-Rose Depp.