He is known for his roles as Nick Clark on Fear the Walking Dead (2015–2018) and 16-year-old Tom Riddle in the film Harry Potter and the Half-Blood Prince (2009).

His mother, Naomi Wirthner, is British and Afro-Jamaican;[citation needed] she manages a theatre company called The Barebones Project.

[7][better source needed] In July 2013, Dillane played in Candida at Theatre Royal, Bath, directed by Simon Godwin.

[10] Dillane starred as Nick Clark, a "shaggy-haired recovering addict",[11] in the horror drama series Fear the Walking Dead from its debut in 2015 until its fourth season.

[18][19] This adventure-drama film directed by Ron Howard is based on Nathaniel Philbrick's non-fiction book of the same name about the sinking of the American whaling ship Essex in 1820, an event that inspired the novel Moby-Dick.