He earned a nomination for the British Academy Television Award for Best Supporting Actor in 2015 for his performance as Tommy Lee Royce in Happy Valley.

[14][15] Norton then attended the Royal Academy of Dramatic Art (RADA) in London for three years, but left in 2010 six months before graduation to take an acting assignment.

[17] At the Crucible Theatre in Sheffield in 2010, Norton starred in That Face as Henry, an 18-year-old who has dropped out of school to care for his mentally disturbed and drug-dependent mother, played by Frances Barber.

Lynne Walker of The Independent wrote of his performance: "At the centre of it all is Henry who, in James Norton's striking portrayal, is like a young caged animal.

[19] The production toured the UK from March to June and transferred to the Duke of York's Theatre in the West End from July to September.

Norton was acclaimed for his role as Tommy Lee Royce, the villain of the hit crime drama Happy Valley.

Michael Hogan of The Telegraph wrote: "...the breakout star, seen in only a few small parts before this, has been the devilishly handsome James Norton, 29, as the heinous killer Royce, whom he has played with impressive depth."

From 2014 to 2018 Norton played crime-solving vicar Sidney Chambers alongside Robson Green as Police Inspector Geordie Keating in the ITV series Grantchester, based on the stories by James Runcie.

[30][31][32] In 2016, Norton appeared as Prince Andrei Bolkonsky in the BBC miniseries of Andrew Davies' production of War & Peace.

[37] As part of his preparation for his role in McMafia, Norton studied the Russian martial art and health system Systema.

[41] When asked if he was religious, in the context of portraying a vicar in Grantchester, Norton said: "Obviously I have a relationship with religion, because I went to a Catholic school and studied theology.