Vidal, who applied his iconoclastic and sometimes scolding manner to politics as well as his writing, died at his home in the Hollywood Hills, his nephew, Burr Steers, told the Los Angeles Times.
He won a National Book Award in 1993 for "United States Essays, 1952-1992."
Vidal was born Eugene Luther Gore Vidal, Oct. 3, 1925, in West Point, N.Y.
A Democrat, he ran for public office twice -- for the U.S. Senate in California and for the U.S. House of Representatives in New York.
His screenplay credits include "Suddenly, Last Summer" (1959), "Is Paris Burning?" (1966) and "Caligula" (1979).