Fatinitza was the first full-length, three-act operetta by Franz von Suppé. The libretto by F. Zell (a pseudonym for Camillo Walzel) and Richard Genée was based on the libretto to La circassienne by Eugène Scribe (which had been set to music by Daniel Auber in 1861), but with the lead role of Wladimir, a young Russian lieutenant who has to disguise himself as a woman, changed to a trousers role; in other words, a woman played the part of the man who pretended to be a woman.

It premièred on 5 January 1876, at the Carltheater Vienna, and proved a huge success, running for more than a hundred performances, with the march "Vorwärts mit frischem Muth", proving a particular hit. The operetta as a whole is no longer in the popular repertory, but the overture is performed as a stand-alone piece.

Viennese operetta sprang out of an attempt by Viennese composers to imitate Jacques Offenbach's works, after the highly successful performance of Le mariage aux lanternes at the Carltheater in 1858. Franz von Suppé was the most notable of these early composers, and proved instrumental in defining the new subgenre. Grove Music Online names Suppé's Das Pensionat (1860) as "the first successful attempt at a genuine Viennese operetta", and this was followed by several more successes, for Suppé, including Flotte Bursche [de] (1863) and Die schöne Galathée (1865). However, until Fatinitza in 1876, Suppé did not write a full-length operetta, and, despite the successes of his shorter works, neither he, nor other Viennese composers such as Giovanni von Zaytz, were able to compete with Offenbach for popularity throughout the 1860s.

Offenbach's dominance was finally challenged with the arrival of Johann Strauss II upon the scene in the 1870s, with works such as Indigo und die vierzig Räuber, Der Karneval in Rom, Die Fledermaus, and others serving to develop and codify the genre Suppé had begun laying out.

Suppé finally tried his hand at a full-length operetta in 1876. F. Zell (a pseudonym for Camillo Walzel) and Richard Genée, who had previously adapted the French play Le Réveillon into Strauss's Die Fledermaus – the "most celebrated of all Viennese operas" according to the musicologist Andrew Lamb – returned to French sources, adapting Eugène Scribe's libretto from Daniel Auber's La circassienne (1861) into Fatinitza. The work premièred at the Carltheater on 5 January 1876, and would prove to be an international success.

Note: This article uses the names found in the original German libretto. Translations of Fatinitza may change characters' names to a greater or lesser extent.

Before the piece begins, Wladimir Samoiloff, a young Russian Lieutenant, had an adventure in which he ended up disguising himself as a woman (whom he named Fatinitza), and met with the hot-tempered elderly General Kantschukoff, who fell in love with his disguise. Wladimir, however, is in love with the General's niece, Lydia.

The operetta opens on a camp of Russian soldiers near Rustchuk, where Wladimir has been assigned. His friend, Julian, a special newspaper correspondent, is mistaken for a spy and dragged to the camp, but Wladimir defuses the situation. Julian and Wladimir reminisce about his Fatinitza disguise, which eventually leads the soldiers to consider some amateur theatre, to relieve the boredom. As no women are present, Wladimir resumes his Fatinitza disguise.