Austen's first acting job was portraying rent boy Anto in an episode of the UK series Shameless in 2010. He played multi-episode roles on The Borgias and Beaver Falls in 2012, and starred as Marc Bayard in the police procedural series Jo in 2013. After his costarring role as Grantchester's Guy Hopkins in 2014, Austen began portraying duplicitous bodyguard Jasper Frost on the E! drama series The Royals in 2015.