Born a poverty-stricken orphan, Natalina, known as Lina, Cavalieri, sold flowers on the streets of Rome and then packed copies for one of the local newspapers. After running away from her convent orphanage home, she made her first appearance in a café in Rome's Piazza Navona, where she passed a hat for donations. She was thirteen years old.

While taking vocal lessons, Lina joined a theatrical troupe progressing to grander establishments, adopting more fashionable dresses and replacing the cheap costume jewelry with more expensive jewels. She studied with the top Italian singers of the day and made her public debut in Lisbon, 1900. After conquering the most fashionable centers for music and arts in Naples, Lina Cavalieri, also skilled in graceful dancing, made her way to Paris, achieving remarkable success at the Folies Bergère, ranking with Cécile Sorel and Caroline Otero as one of the queens of the Belle Époque.

A café singer of world renown, Lina Cavalieri went on to sing a great variety of roles in Europe and America, eventually appearing in the world's greatest music halls. In 1897 she also made her Russian debut with phenomenal success. It was only the first of many visits there and while her success was constant, she was not free from substantial whiffs of scandal, both artistic and personal.

Promoted by others and by herself as "the most beautiful woman in the world, the Lina's love life always made good copy. By the time she reached 20, Lina sported valuable trophies from half the crowned heads of Europe and anyone else rich enough to suit her tastes including Russian Prince Alexander Bariatinsky (to whom she claimed to have married) and Benito Mussolini. Writer Gabriele D'Annunzio claimed that Lina Cavalieri was "the most perfect personification of Venus on Earth" and the tenor Leonid Sobinov described her as "a marvelous flower, loving, fragrant with spring orchids". These were only two of the many fulsome descriptions of her at this time.

Lina became "the most beautiful singer ever to appear on the stage during the 19th century." Adoring audiences were enslaved by her face, figure, elegance, and natural attributes all of which were enhanced by sumptuous gowns and jewels (especially emeralds), as seen through the unbelievable numbers of postcards and photographs made of her for all the thousands who would never see her in the theater. She also starred in nine silent films, although the ninth film appears to have never been completed.

While Lina Cavalieri was one of the most prominent stars of her era, it seems that her fame owed more to her appearance than to her art, not to mention the scandalous behavior between she and her rival, La Belle Otero.

After retiring from the stage, she managed her own cosmetic salons in Paris. She invented her own beauty concoctions for every part of her body including bizarre cold cream mixtures, which she believed would alleviate wrinkles, keeping her young and beautiful. In 1914 she published a beauty book, "My Secrets of Beauty" and continued to write, contributing beauty tips for a women's magazine called "Femina".

Lina Cavalieri was also known for her generosity. She campaigned for orphans and entertained the French troops during WWI. She went on to become a nurse during WWII, dying in an air raid just outside Florence in 1944.