Ekberg, who had long been living in Italy, had been hospitalised recently due to several unspecified illnesses, her lawyer Patrizia Ubaldi said, confirming her death. She had been in a wheelchair for several years after breaking a hip.
Ekberg was one of cinema's most famous "sex goddesses," as renowned for her performances as she was for her alleged list of romances with major stars such as Frank Sinatra and Gary Cooper. In addition to "La Dolce Vita," which made her an international film icon, Ekberg starred in "War and Peace" with Audrey Hepburn, "Artists and Models" with Jerry Lewis and Dean Martin and "Paris Holiday" with Bob Hope.
She auditioned for, but lost out on, the part of Honey Ryder in the first James Bond film, "Dr. No." Along with Marilyn Monroe, Ekberg was one of the most popular pinups of the 1950s.
A former Miss Sweden, Ekberg snagged a Golden Globe for Most Promising Newcomer for one of her initial Hollywood forays, the 1955 thriller "Blood Alley" with John Wayne and Lauren Bacall.
Ekberg was born in Malmo, Sweden, on Sept. 29, 1931, the sixth of eight children. After doing some modeling in her teens she started her showbiz career in 1951 when she won the Miss Sweden title and then traveled to the U.S. to compete for the Miss Universe crown, which she didn't win. She was put under contract by Universal instead.
As a Universal starlet during the 1950s Ekberg landed small roles in pics including "Abbott and Costello Go to Mars," in which she played a voluptuous guard on Venus, and "The Golden Blade." She also appeared on several Bob Hope TV specials, where her bombshell curves were fodder for Hope's jokes.
Federico Fellini's 1960 "La Dolce Vita," in which Ekberg played Sylvia, a movie star pestered by paparazzi who dips into the Trevi fountain in a strapless black dress and calls out "Marcello," shot her to super-stardom.
Hosting Swedish radio show "Sommar" in 2005, Ekberg recalled shooting the Trevi Fountain scene in February, when the water in the fountain was cold and Mastroianni was drunk on vodka.
"And there I was. I was freezing," she said. "They had to lift me out of the water because I couldn't feel my legs anymore," she said.
In 1963 Ekberg co-starred with Ursula Andress, Frank Sinatra, and Dean Martin in the western-comedy "4 for Texas," directed by Robert Aldrich.
Ekberg was married twice; first to actor Anthony Steel from 1956 to 1959 and later to actor Rik Van Nutter from 1963 to 1975. She had no children.
Though she made more than 50 films over five decades, by the late 1970s Ekberg's career had taken a dive and she nearly stopped working. Her most recent role was playing a character named Ingrid in Italian TV series "Il Bello Delle Donne," produced by Silvio Berlusconi's Mediaset.
According to Italian press reports, Ekberg died almost penniless.
In December 2011, Italian newspapers reported that the then 80-year-old Ekberg was "destitute" after spending more than three months in a Rimini hospital with a broken thigh. During this time her home had been robbed and also damaged in a fire. Ekberg then applied for financial help from the Fellini Foundation.
Her lawyer, Ubaldi, said a ceremony would be held in coming days at a Lutheran church in Rome.