"Vidal died Tuesday at his home in the Hollywood Hills of complications of pneumonia," the Los Angeles Times said, quoting the author's nephew Burr Steers.
Vidal's literary legacy includes a series of historical novels – Burr, 1876, Lincoln and The Golden Age among them – as well as the campy transexual comedy Myra Breckenridge.
He started writing as a 19-year-old soldier stationed in Alaska, basing Williwaw on his World War II experiences. His third book, The City and the Pillar, created a sensation in 1948 because it was one of the first open portrayals of a homosexual main character.
Vidal referred to himself as a "gentleman bitch" and was as egotistical and caustic as he was elegant and brilliant.
In addition to rubbing shoulders with the great writers of his time, he banged heads with many of them. Vidal considered Ernest Hemingway a joke and compared Truman Capote to a "filthy animal that has found its way into the house".
His most famous literary enemies were conservative pundit William F Buckley Jr and writer Norman Mailer, who Vidal once likened to cult killer Charles Manson.
Mailer head-butted Vidal before a television appearance and on another occasion knocked him to the ground.
Vidal and Buckley took their feud to live national television while serving as commentators at the 1968 Democratic National Convention. Vidal accused Buckley of being a "pro-crypto-Nazi" while Buckley called Vidal a "queer" and threatened to punch him.
Vidal seemed to make no effort to curb his abundant ego.
In a 2008 interview with Esquire magazine Vidal said people were always seemed impressed that he had met so many famous people, such as Jacqueline Kennedy and William Burroughs.
"People always put that sentence the wrong way around," he said. "I mean, why not put it the true way – that these people got to meet me, and wanted to?"
Eugene Luther Vidal Jr was born in West Point, New York, and eventually took his mother's surname as his first name. He grew up in Washington, DC, where his grandfather, Democratic US senator Thomas Gore of Oklahoma, had a strong influence on the boy. The young Vidal developed an interest in politics as he read to the blind senator and led him about town.
He went to exclusive private secondary schools but did not attend college.
After his parents divorced, Vidal's mother married Hugh Auchincloss, who later also became the stepfather of Jacqueline Kennedy. That connection gave Vidal access to the Kennedy White House before a falling out with the family.
After early success, his literary career stalled – perhaps because of the controversy of The City and the Pillar – and he concentrated on television and movie scripts.
Vidal got back on track in the 1960s with Julian, about a Roman emperor; Washington, DC, the tale of a political family; and Myra Breckenridge. Bigger success followed with recreations of historical US figures – such as Aaron Burr and Abraham Lincoln – that analyse where Vidal thought America fell from grace.
Vidal also was known for his sharp essays on society, sex, literature and politics. He was especially fervent about politics and what he considered to be the death of "the American Empire".
"The genius of our ruling class is that it has kept a majority of the people from ever questioning the inequity of a system where most people drudge along, paying heavy taxes for which they get nothing in return," he once said.
In 1960 Vidal, a distant cousin of former vice president Al Gore, ran unsuccessfully for a congressional seat in New York and in 1982 failed in a bid for a California Senate seat.
He once described the US as "the land of the dull and the home of the literal" and starting in the 1960s lived much of the time in a seaside Italian villa. He moved back permanently in 2003, shortly before Howard Austen, his companion of more than 50 years, died of cancer. – Reuters