• Amilcare Ponchielli. Dramma lirico in four acts. 1876.
• Libretto by Arrigo Boito (disguised under the anagram of Tobia Gorrio), after Victor Hugo's play Angélo, tyran de Padoue (Angelo, Tyrant of Padua).
• First performance at the Teatro alla Scala, Milan, on 8th April 1876.

In 17th century Venice it is Carnival. The spy Barnaba tries to force his attentions on the singer La Gioconda, whose blind mother, through Barnaba, is now popularly suspected of witchcraft. Alvise and his wife Laura intervene, the latter convincing her husband of La Cieca's innocence, to receive a rosary from the grateful woman. Gioconda is betrothed to Enzo, disguised as a sailor, but recognised by Barnaba as a proscribed prince of Genoa and Laura's former suitor. Enzo's love for Laura is now renewed, to the dismay of Gioconda, who overhears a plot between Enzo and Barnaba, the latter having offered to arrange a meeting for Enzo with Laura. In the second act Laura is re-united with Enzo, by night on his ship, but their meeting, arranged by Barnaba, is interrupted by Gioconda. Her anger is inevitably mollified when she sees the rosary her mother had given Laura and helps her rival to escape, when Alvise, warned by Barnaba, approaches the vessel. Enzo, spurning Gioconda once more, sets the ship on fire and leaps into the sea. In his palace Alvise plots revenge, giving Laura a phial of poison, to be drunk before the end of a gondolier's song that can be heard from the lagoon. Gioconda, coming to her aid, substitutes for the poison a narcotic that will simulate death. Guests to the palace are entertained by the Dance of the Hours. Barnaba appears, dragging in La Cieca, who warns of impending death. Alvise reveals Laura's body, telling his guests what he has done, and Enzo, who has entered secretly, rushes at him. The fourth act, on the Giudecca, finds Gioconda, with the drugged Laura, but planning her own death, having gained Enzo's release by promising to yield to Barnaba. Enzo and Laura make their escape together, while Gioconda, facing Barnaba, stabs herself, dying before she can hear Barnaba's claim that he has drowned her mother.

Ponchielli undertook various revisions to his grand opera in the years immediately following its first staging. The work, continuing in international repertoire, makes heavy demands for its staging. The third act ballet, the Dance of the Hours, is very familiar, with Enzo's ecstatic aria Cielo e mar (Heaven and sea), as he waits on his ship for the appearance of Laura. Gioconda's fourth act dilemma, Suicidio... in questi fieri momenti tu sol mi resti (Suicide.. in these cruel moments you alone remain for me) provides a moment of tense drama, as does the first act recognition scene between Barnaba and Enzo, Enzo Grimaldo, Principe di Santafior, che pensi? (Enzo Grimaldo, Prince of Santafior, what are you thinking?).