Valentino was born Rodolfo Alfonso Raffaello Piero Filiberto Guglielmi in Castellaneta, Italy, to a French mother, Marie Berthe Gabrielle Barbin, and Giovanni Antonio Giuseppe Fidele Guglielmi, a veterinarian who died of malaria when Valentino was 11. As a child, Valentino was reportedly spoiled and troublesome. His mother coddled him while his father disapproved of his behavior. He did poorly in school, and was eventually enrolled in agricultural school where he received a degree. After living in Paris in 1912, he soon returned to Italy. Unable to secure employment, he departed for the United States. Arriving in New York City, Valentino soon ran out of money and spent a period of time on the streets. He eventually supported himself with jobs such as bussing tables in restaurants and gardening. Eventually, he found work as a taxi dancer.

In 1917, Valentino joined an operetta company that traveled to Utah where it disbanded. He then joined an Al Jolson production of Robinison Crusoe Jr., travelling to Los Angeles. By fall, he was in San Francisco with a bit part in a theatrical production of Nobody Home. While in town, Valentino met actor Norman Kerry, who convinced him to try a career in cinema, still in the silent film era.

His first part was as an extra in the film Alimony, moving on to small parts in several films. Despite his best efforts he was typically cast as a "heavy" (villain) or gangster. At the time, the major male star was Douglas Fairbanks, with a fair complexion, light eyes, and an All American look, with Valentino the opposite, eventually supplanting Sessue Hayakawa as Hollywood's most popular "exotic" male lead.

While traveling to Palm Springs, Florida to film Stolen Moments, Valentino read the novel The Four Horsemen of the Apocalypse by Vicente Blasco Ibáñez. Seeking out a trade paper, he discovered that Metro had bought the film rights to the story. In New York, he sought out Metro's Office, only to find June Mathis had been trying to find him. She cast him in the role of Julio Desnoyers. The Four Horsemen of the Apocalypse, was released in 1921, becoming a commercial and critical success. It was one of the first films to make $1,000,000 at the box office, as well as the 6th best selling silent film ever.

Valentino's final film for Metro was The Conquering Power. The film received critical acclaim and did well at the box office. After the film's release, Valentino made a trip to New York where he met with several French producers. Yearning for Europe, better pay, and more respect, Valentino returned and promptly quit Metro. After quitting Metro, Valentino took up with Famous Players-Lasky, a studio which films that were more commercially focused. Jesse Lasky intended to capitalize on the star of Valentino, and cast him in a role that would solidify his reputation as the "Latin Lover". In The Sheik. Valentino played the starring role as Sheik Ahmed Ben Hassan. The film was a major success and would go on to define not only his career but his image and legacy. Valentino tried to distant the character from a stereotypical portrayal of an Arab man.

In 1922, Valentino began work on Blood and Sand. Co-starring Lila Lee and Nita Naldi, Valentino played the lead, bullfighter Juan Gallardo. The film was a success, with critics calling it a masterpiece on par with Broken Blossoms and Four Horsemen. Blood and Sand went on to become one of the top 4 grossing movies of 1922, breaking attendance records, and grossing $37,400 at the Rivoli Theatre alone. Valentino would consider this one of his best films.

The first film under the contract signed with Ritz-Carlton Pictures was Monsieur Beaucaire, wherein Valentino played the lead, Duke of Chartres. The film did poorly and American audiences found it 'effeminate'. During the filming of Monsieur Beaucaire, both Charlie Chaplinand Douglas Fairbanks approached Valentino privately, due to his contract with Ritz Carlton, about joining with United Artists. Valentino's contract with United Artists provided $10,000 a week for only three pictures a year, plus a percentage of his films. Valentino chose his first UA project, The Eagle.

Valentino was very sensitive with his public perception. Women loved him and thought him the epitome of romance. However, American men were less impressed, walking out of his movies in disgust. With the Fairbanks type being the epitome of manhood, Valentino was seen as a threat to the All American man.

In 1923, Valentino published a book of poetry which entitled Day Dreams. He would later serialize events in various magazines. Valentino was fascinated with every part of movie-making. During production on a Mae Murray film he spent time studying the director's plans. He craved authenticity and wished to shoot on location, finally forming his own production company, Rudolph Valentino Productions, in 1925. Valentino, George Ullman, and Beatrice Ullman were the incorporators.

On May 14, 1923, while in New York City, Valentino made his only two vocal recordings; "Kashmiri Song" ("The Sheik") and "El Relicario" ("Blood and Sand"). The recordings were not released until after Valentino's death.

Valentino was one of the first in Hollywood to offer an award for artist accomplishments in films. The Academy Awards would later follow suit. In 1925, he gave out his one and only medal, to John Barrymore, for his performance in Beau Brummell. The award, named The Rudolph Valentino Medal, required the agreement of Valentino, two judges and the votes of 75 critics.

On August 15, 1926, Valentino collapsed at the Hotel Ambassador in New York City. He was hospitalized at the Polyclinic in New York and underwent surgery for a perforated ulcer. The surgery went well and he seemed to be recovering when peritonitis set in and spread throughout his body. He died eight days later, at the age of 31.

The life of Rudolph Valentino has been filmed a number of times for television and the big screen. One of these biopics is Ken Russell's 1977 film, Valentino, in which Valentino is portrayed by Rudolf Nureyev. The film itself is only loosely based on his life.