Over more than half a century, he appeared in more than 80 TV productions and about 20 films.
His movie career began in 1964 with a part as a ship's officer in “Ensign Pulver.” He often played a military man, including roles in “The Eagle Has Landed” (1976) and “Superman” (1978). One of his more affecting roles was as Art Carney's self-pitying son in “Harry and Tonto” (1974).
On television, he started out in drama anthologies and starred in three short-lived series — two early 1970s sitcoms, “The Good Life” and “Here We Go Again,” and the 1997 legal drama “Orleans.”
When he returned to the role of J.R. Ewing in a new version of “Dallas,” which debuted on TNT in June, Times critic Robert Lloyd wrote that it was “Hagman’s show” and said that the series would not be worth watching without him.
During his first run on “Dallas,” he bought a mountaintop property in Ojai and spent years building an 18,000-square-foot chateau he called Heaven. The Malibu home he purchased for $115,000 in the 1960s was sold to Sting for nearly $7 million in the 1990s.
In 2005, Hagman's wife was diagnosed with Alzheimer's disease. Four years later, he moved her to an assisted-living facility near another of his homes, in Santa Monica, and put the Ojai house on the market.
For 25 years, he observed “silent Sundays,” refusing to talk, a move he initially made to rest his voice. After giving up cigarettes, he often carried a hand-held fan to blow fumes back toward smokers.
In Malibu, he had long been known as an amiable eccentric who routinely pulled his wardrobe from a vast collection of costumes and hats. He shopped for groceries while wearing a yellow chicken suit and played Frisbee in a Robin Hood hat and karate robe.
“My behavior earned me the nickname the Mad Monk of Malibu,” he wrote in his book. “Living up to it came naturally.”
Hagman’s survivors include his wife, Maj; daughter, Heidi; and son, Preston.