He is best known for his roles in Midsomer Murders (2013–2016), A Song for Jenny (2015), Jamestown (2017), Top End Wedding (2019), The Great (2020–2023), and for playing guitarist Brian May in the Queen biopic Bohemian Rhapsody (2018).

Lee was commended in the 2008 Ian Charleson Awards for his appearance in the National Theatre's production of Oedipus and in 2009 played Laertes to Jude Law's Hamlet in the Donmar West End season.

[5] He won first prize of the 2011 Ian Charleson Award for his role as Edgar in the 2010 King Lear production at the Donmar Warehouse.

[7] At Christmas 2013, Lee began a television starring role as DCI Barnaby's new sergeant, DS Charlie Nelson, in the 16th series of Midsomer Murders, which also included the show's 100th episode, partially shot in Denmark in collaboration with the local national broadcasting corporation, DR.[8] In early 2014 he appeared in Versailles at the Donmar Warehouse.

[9] Lee played guitarist Brian May in the Queen biopic Bohemian Rhapsody (2018),[10] which earned him a nomination for Outstanding Performance by a Cast in a Motion Picture at the 25th Screen Actors Guild Awards.