Aneurin Barnard was first seen in the adventure drama television series ‘Jacob's Ladder’ in 2003. He next appeared in television series ‘Y Pris’ (2007), ‘Casualty’ (2008), and ‘Doctors’ (2009), before making his big-screen debut in the 2011 British action-adventure war film ‘Ironclad’ directed by Jonathan English. The film received a mixed response from critics and sits on a 42% approval rating on Rotten Tomatoes. That same year, he also starred in the Marc Evans-directed British independent musical film ‘Hunky Dory.’ The film had its premiere at the 55th BFI London Film Festival. In 2012, he played the role of ‘Tommy’ in the Irish psychological horror film ‘Citadel’ directed by Ciarán Foy. The film received a 56% rating on Rotten Tomatoes. The same year also saw the release of the Ryan Andrews-directed British horror film ‘Elfie Hopkins’ where Barnard starred as ‘Dylan.’ The film was panned by critics and scored a 0% rating on Rotten Tomatoes. In 2013, he portrayed ‘Richard III of England’ in the British historical drama television drama ‘The White Queen.’ The series was nominated for 3 ‘Golden Globe Awards’ and 4 ‘Primetime Emmy Awards’ along with a ‘People's Choice Award.’
Barnard continued to star in films and television series such as ‘The Truth About Emanuel’ (2013), ‘Mary Queen of Scots’ (2013), ‘The Adventurer: The Curse of the Midas Box’ (2014), ‘Cilla’ (2014), ‘Killing Jesus’ (2015), ‘War & Peace’ (2016), ‘Thirteen’ (2016), ‘Bitter Harvest’ (2017), ‘Interlude in Prague’ (2017), ‘Dunkirk’ (2017), ‘Dead In A Week (or your money back)’ (2018), ‘The Personal History of David Copperfield’ (2019), ‘The Goldfinch’ (2019), ‘Barkskins’ (2020), and ‘The Pact’ (2021). He was last seen playing the role of ‘Doctor Holford’ in the British crime drama television series ‘Peaky Blinders’ in 2022.