He built an army of fans by displaying his muscular torso as the smouldering Mr Darcy in Pride And Prejudice 20 years ago.
Six years later, he was almost as hunky as Mark Darcy in Bridget Jones's Diary. Even when accepting his Oscar for The King's Speech in 2011, Firth maintained a cherubic smile.
But nowadays the 55-year-old actor appears to have settled on a more slimline look having shed several pounds.
Firth, who was pictured at a London Fashion Week party on Monday night, first slimmed down for his role as a prisoner of war suffering at the hands of the Japanese in 2013's The Railway Man.