She was born Natalina Cavalieri on Christmas Day in 1874 in Viterbo, Latium, Italy. She lost her parents at the age of 15 and became a ward of the state. She was sent to live in a Roman Catholic orphanage where the strictness of the nuns prompted her to run away at her first opportunity. Mixed reports say she ran away with a touring theatrical company, worked in a tailor shop, as a flower seller and newspaper packer in Rome and sang in Naples's street cafes. Eventually she made her way to Paris where she sang at the Folies Bergere and saved enough to begin her voice and singing studies under Mme. Marchesi with whom she worked diligently for two years. Later she went back to Italy to study some more under Mariani Masi. Some say those voice lessons in Italy were paid for by the Russian Prince Alexander Bariatinsky whom she had met in St. Petersburg, Russia where she was wildly successful singing all the leading opera roles. It is uncertain whether she was married to Bariatinsky or was his mistress. Soon she became quite successful in Milan, Monte Carlo and then Paris. She co-stared at the New York Metropolitan Opera in the Umberto Giordano opera, Fedora with the great Enrico Caruso in December 1906. She remained at the Metropolitan for two more years starring again with Caruso in Puccini's Manon Lescaut in 1907. During the 1909-1910 season she sang with Oscar Hammerstein's Manhatten Opera Company.
She became a famous beauty of le Belle Epoque and audiences flocked to see her as well as hear her. Considered the most beautiful woman in the world she was also the most photographed star of her time. She had amassed a fortune in just a few short years since her debut. Married four times, she was considered to have a classical beauty, with charm and personality free from affectation and her taste in dress was exquisite. Wherever she sang in Italy standing room was at a premium.
After retiring from the stage Lina Cavalieri ran a cosmetic salon in Paris, wrote an advice column for make-up for women, and published a book, My Secrets of Beauty in 1914 at the age of 40 which detailed over a thousand valuable recipes for beauty and bath preparations of her own. The next year she returned to Italy to make motion pictures. When Italy became involved in WWI Lina went to the United States where she made four more silent films. When WWII broke out and she was well into her 60s, she nevertheless worked as a volunteer nurse when she was killed in 1944 in an Allied bombing raid that destroyed her home on the outskirts of Florence. Her portrait was painted several times by well known artists of her day, her likeness was depicted numerously in Piero Fornasetti's designs. A movie was made in 1955 about her life starring Gina Lollobrigida and in 2004 a book was written about her life. Postcards from the many photographs taken of her have become collectible.