Tributes were yesterday paid to the US actor, who was known internationally for his role as merciless oil magnate JR Ewing in the TV soap.
Linda Gray, who played his on-screen wife Sue Ellen Ewing and was a long-time friend, was reportedly by his bedside when he died in hospital in Dallas, Texas. He was 81.
Hagman, who had suffered from cancer and liver disease, had been filming the next series of the show, which was relaunched earlier this year. Channel 5 said his death would be incorporated into the soap's storyline.
Gray paid tribute to her co-star Hagman, who she described as her "best friend for 35 years".
A joint statement from the producers, cast and crew of Dallas said: "Larry Hagman was a giant, a larger-than-life personality whose iconic performance as JR Ewing will endure as one of the most indelible in entertainment history."