[5][failed verification][better source needed] He has a younger sister, Lillie Flynn, who sings with the Sussex Wit.

[8] In 2014, Flynn played the lead role of Dylan in the rom-com television series Scrotal Recall which aired on Channel 4.

Also in 2017, he played Pascal Renouf, a secretive outsider suspected of a series of brutal murders in director/writer Michael Pearce's debut dark thriller Beast, which premiered at the Toronto International Film Festival and was released in the UK on 27 April 2018.

[12][13] In 2018, Flynn played William Dobbin in the ITV and Amazon Studios television serial adaptation of Vanity Fair.

[15] In 2019, he starred as David Bowie in the drama Stardust, based on a screenplay by Christopher Bell and directed by Gabriel Range.

[17] In 2020, he starred in Emma,[18] Autumn de Wilde's adaptation of Jane Austen's novel of the same name, alongside Anya Taylor-Joy, Bill Nighy, and Josh O'Connor.

He wrote the song played over the ending credits, "Queen Bee," which was released as a single alongside the film.

[25] Flynn performed in Propeller's all-male Shakespeare troupe, playing Curtis (The Taming of the Shrew) and Sebastian (Twelfth Night) in the 2007 season.

[27] Flynn was cast in the role of Lee in Jerusalem, Jez Butterworth's hit play, for which he was nominated for an Olivier Award for best supporting actor.

[33] The production was recorded as an audio play, released by Audible,[34] which features original music by Flynn.

The story of how Burton and Sir John Gielgud clashed as they staged Hamlet on Broadway in 1964, the production received rave reviews, particularly the performances of the two leads.

[38][39] His second album Been Listening featured a duet with fellow British folk musician Laura Marling on the track "The Water".

[41] In May 2021, Flynn released Lost in the Cedar Wood, a collaboration with nature writer Robert Macfarlane.

This includes writing the film score for the 2012 film A Bag of Hammers, and the score and theme song of the BBC Four television series Detectorists,[44] which he performed in a cameo appearance as a performer at an open mic night in series one, episode three.

[46] Flynn and Joe Zeitlin are the theme music composers for the 2019 Netflix TV Mini Series, The Last Czars.

[47] He co-wrote the song Coins for Eyes with Robert Macfarlane for the 9th series of the BBC archaeology programme Digging for Britain.

[57] He won a commendation in the 2012 Ian Charleson Awards for his role as Viola in Twelfth Night at the Globe Theatre.

[59] His radio play Magnitsky the Musical won Best Original Single Drama at the BBC Audio Awards in 2021.