[3][2][4] Smyth began her acting career in 2012, in British crime drama film Ill Manors alongside Riz Ahmed, Ed Skrein and Jo Hartley.
[7] In 2015, Smyth landed a recurring role as Flora on the television series The Frankenstein Chronicles appearing alongside Sean Bean.
[8] In 2016, Smyth secured a main role as Lucy Wells in 24 episodes of Harlots, a series about a brothel in 18th-century London.
[8][9] In 2017, Smyth played Yeva Podnikov for nine episodes of Sky Atlantic television series Fortitude.
[11] The same year, Smyth starred alongside Jonathan Rhys Meyers in the Stephan Rick directed The Good Neighbor, a film in which her character 'Vanessa' forms a romantic bond with her sister's killer.