Cavalleria rusticana (pronounced [kavalleˈriːa rustiˈkaːna]; Italian for 'Rustic Chivalry') is an opera in one act by Pietro Mascagni to an Italian libretto by Giovanni Targioni-Tozzetti and Guido Menasci, adapted from an 1880 short story of the same name and subsequent play by Giovanni Verga. Considered one of the classic verismo operas, it premiered on 17 May 1890 at the Teatro Costanzi in Rome. Since 1893, it has often been performed in a so-called Cav/Pag double-bill with Pagliacci by Ruggero Leoncavallo.

In July 1888 the Milanese music publisher Edoardo Sonzogno announced a competition open to all young Italian composers who had not yet had an opera performed on stage. They were invited to submit a one-act opera which would be judged by a jury of five prominent Italian critics and composers. The best three would be staged in Rome at Sonzogno's expense.

Mascagni heard about the competition only two months before the closing date and asked his friend Giovanni Targioni-Tozzetti, a poet and professor of literature at the Italian Royal Naval Academy in Livorno, to provide a libretto. Targioni-Tozzetti chose Cavalleria rusticana, a popular short story (and play) by Giovanni Verga, as the basis for the opera. He and his colleague Guido Menasci set about composing the libretto, sending it to Mascagni in fragments, sometimes only a few verses at a time on the back of a postcard. As Mascagni believed that the work was hastily written and not reflective of his best efforts, his courage deserted him and he placed the draft in a drawer, from where his wife, Argenide Marcellina "Lina" Mascagni, removed it and submitted it on the last day that entries would be accepted. In all, 73 operas were submitted, and on 5 March 1890, the judges selected the final three: Niccola Spinelli's Labilia, Vincenzo Ferroni [it]'s Rudello, and Mascagni's Cavalleria rusticana.

There have been two other operas based on Verga's story. The first, Mala Pasqua! (Bad Easter!) by Stanislao Gastaldon, was entered in the same competition as Mascagni's. However, Gastaldon withdrew it when he received an opportunity to have it performed at the Teatro Costanzi, where it premiered on 9 April 1890. In the 1907 Sonzogno competition, Domenico Monleone submitted an opera based on the story, and likewise called Cavalleria rusticana. The opera was not successful in the competition but premiered later that year in Amsterdam and went on to a successful tour throughout Europe, ending in Turin. Sonzogno, wishing to protect the lucrative property which Mascagni's version had become, took legal action and successfully had Monleone's opera banned from performance in Italy. Monleone changed the opera 'beyond recognition', setting the music to a new libretto. In this form it was presented as La giostra dei falchi in 1914.

Cavalleria rusticana opened on the evening of 17 May 1890 at the Teatro Costanzi in Rome to a half empty house. However, the audience included not only the most authoritative music critics in the country but also Queen Margherita, a great music lover. It was a success from its opening notes. Following Stagno's rendition of the Siciliana behind the curtain, the audience leapt to their feet with a thunderous applause not heard for many years. The Siciliana was encored as were several other numbers in the opera. It was a sensation, with Mascagni taking 40 curtain calls and winning the First Prize.

Although Mascagni had started writing two other operas earlier (Pinotta, premiered in 1932, and Guglielmo Ratcliff, premiered in 1895), Cavalleria rusticana was his first opera to be completed and performed. It remains the best known of his fifteen operas and one operetta (Sì). Apart from Cavalleria rusticana, only Iris and L'amico Fritz have remained in the standard repertory, with Isabeau and Il piccolo Marat on the fringes of the Italian repertoire. At the time of Mascagni's death in 1945, the opera had been performed more than 14,000 times in Italy alone.

In 1890, following its run of sold-out performances at the Teatro Costanzi, the opera was produced throughout Italy and in Berlin. Cavalleria Rusticana had its Western Hemisphere premiere at the Teatro Nacional in Buenos Aires on 28 February 1891, and a further run of performances at the Teatro de la Opera from 5 August 1891. It received its London premiere at the Shaftesbury Theatre on 19 October 1891 and its Covent Garden premiere on 16 May 1892.

American producers vied with each other (sometimes through the courts) to be the first to present the opera in that country. Cavalleria rusticana finally had its American premiere in Philadelphia at the Grand Opera House on 9 September 1891, followed by a performance in Chicago on 30 September 1891. The opera premiered in New York City on 1 October 1891, with two rival performances on the same day: an afternoon performance at the Casino, directed by Rudolph Aronson, and an evening performance at the Lenox Lyceum, directed by Oscar Hammerstein.