Ruggero (or Ruggiero) Leoncavallo (23 April 1857 – 9 August 1919) was an Italian opera composer and librettist. Throughout his career, Leoncavallo produced numerous operas and songs, but it is his 1892 opera Pagliacci that remained his lasting contribution, despite attempts to escape the shadow of his greatest success. Today Pagliacci continues to be his most famous opera and one of the most popular and frequently performed works in the operatic repertory. His other notable compositions include the song "Mattinata", popularized by Enrico Caruso, and, to a lesser extent, his version of La bohème which, however, was overshadowed by Puccini's highly successful opera of the same name.

I Medici is an opera in four acts composed by Ruggero Leoncavallo, with a libretto by the composer. Set in Renaissance Florence at the court of Lorenzo de' Medici, it was intended as the first part of a planned but unfinished trilogy called Crepusculum. The opera premiered on 6 November 1893 at the Teatro Dal Verme in Milan.

La bohème is an Italian opera in four acts, with music and libretto by Ruggero Leoncavallo, based on Scènes de la vie de bohème (1851) by Henri Murger. The opera received a successful premiere at the Teatro la Fenice, Venice, on 6 May 1897. Leoncavallo wrote his opera La bohème contemporaneously with Giacomo Puccini's own treatment of the same story. Leoncavallo later revised the work, titling it Mimì Pinson, but despite initial respect, it did not survive. Puccini's version has become a standard in the operatic repertoire, whereas Leoncavallo's opera is rarely performed. Leoncavallo's version did not receive its UK premiere until May 1970. Allan Atlas has analysed in detail the different treatments of the death of the Mimì character in both Leoncavallo's and Puccini's versions of La bohème, contrasting the historical success of Puccini's opera and the relative failure of Leoncavallo's.

Pagliacci (Italian pronunciation: [paʎˈʎattʃi]; literal translation, 'Clowns') is an Italian opera in a prologue and two acts, with music and libretto by Ruggero Leoncavallo. The opera tells the tale of Canio, actor and leader of a commedia dell'arte theatrical company, who murders his wife Nedda and her lover Silvio on stage during a performance. Canio portrays on stage the character of Pagliaccio (Pierrot), while Nedda portays Pierrot's unfaithful lover Columbina. Pagliacci premiered at the Teatro Dal Verme in Milan on 21 May 1892, conducted by Arturo Toscanini, with Adelina Stehle as Nedda, Fiorello Giraud as Canio, Victor Maurel as Tonio, and Mario Ancona as Silvio. Soon after its Italian premiere, the opera played in London (with Nellie Melba as Nedda) and in New York (on 15 June 1893, with Agostino Montegriffo as Canio). Pagliacci is the best-known of Leoncavallo's ten operas and remains a staple of the repertoire. Pagliacci is often staged with Cavalleria rusticana by Pietro Mascagni, a double bill known colloquially as "Cav/Pag".

Ruggero (or Ruggiero) Leoncavallo (23 April 1857 – 9 August 1919) was an Italian opera composer and librettist. Throughout his career, Leoncavallo produced numerous operas and songs, but it is his 1892 opera Pagliacci that remained his lasting contribution, despite attempts to escape the shadow of his greatest success. Today Pagliacci continues to be his most famous opera and one of the most popular and frequently performed works in the operatic repertory. His other notable compositions include the song "Mattinata", popularized by Enrico Caruso, and, to a lesser extent, his version of La bohème which, however, was overshadowed by Puccini's highly successful opera of the same name.

Ruggero (or Ruggiero) Leoncavallo (23 April 1857 – 9 August 1919) was an Italian opera composer and librettist. Throughout his career, Leoncavallo produced numerous operas and songs, but it is his 1892 opera Pagliacci that remained his lasting contribution, despite attempts to escape the shadow of his greatest success. Today Pagliacci continues to be his most famous opera and one of the most popular and frequently performed works in the operatic repertory. His other notable compositions include the song "Mattinata", popularized by Enrico Caruso, and, to a lesser extent, his version of La bohème which, however, was overshadowed by Puccini's highly successful opera of the same name.