Ruggero Leoncavallo was born in Naples on March 5, 1858. He trained at the Naples Conservatory and earned a living by playing in various cafes and composing operas (although most of his operas went unnoticed by critics and audiences). The success of Mascagni's Cavalleria Rusticana in 1890 spurred Leoncavallo on to create a verismo style opera of his own with Pagliacci in 1892. Pagliacci premiered at the Teatro dal Verme in Milan, with Toscanini as conductor to rave reviews and Leoncavallo had his first (and only) operatic success. Leoncavallo's libretto was based on Catulle Mendès' play La Femme de Tabarin (1887), although Leoncavallo's version of how he came to his libretto was more colorful. He claimed it was based on an incident he witnessed as a child. Apparently, he was taken to see a troupe of comedians in Calabria when a man was stabbed by the head of the troupe after being caught with the man's wife.

Because Pagliacci was a one-act opera, it was often paired with other one acts including the opera that sparked Pagliacci's composer, Cavalleria Rusticana. As early as December 1893, the Cav/Pag pairing began and remains the most popular of the pairings. For both composers, each opera represented their only successes.

In 1897, Leoncavallo premiered La Bohème which is one of his finest works, and even though Leoncavallo's version followed Henri Mürger's story more closely than Puccini's, it was completely eclipsed by the success of Puccini's version which premiered in 1896. Leoncavallo wrote another 13 operas and operettas, all of which have been forgotten. Leoncavallo died in Montacatani on August 9, 1919.