Così fan tutte, ossia La scuola degli amanti[a] (Women are like that, or The School for Lovers), K. 588, is an opera buffa in two acts by Wolfgang Amadeus Mozart.

The libretto was written by Lorenzo Da Ponte who also wrote Le nozze di Figaro and Don Giovanni.

Although it is commonly held that Così fan tutte was written and composed at the suggestion of the Emperor Joseph II, recent research does not support this idea.

The words are sung by the three men in act 2, scene 3, just before the finale; this melodic phrase is also quoted in the overture to the opera.

[6] According to William Mann,[8] Mozart disliked prima donna Adriana Ferrarese del Bene, da Ponte's arrogant mistress for whom the role of Fiordiligi had been created.

[9] The subject matter (see synopsis below) did not offend Viennese sensibilities of the time, but in the 19th and early 20th centuries was considered risqué, vulgar, and even immoral.

[10] A comedic adaptation, Covid fan tutte, (also using other music by Mozart) depicting life during the first several months of the COVID-19 pandemic was produced by the Finnish National Opera in 2020.

Despina is occasionally performed by a mezzo-soprano, such as Cecilia Bartoli, Frederica von Stade, Agnes Baltsa, Ann Murray and Ginger Costa-Jackson.

The instrumentation is as follows: Mozart and Da Ponte use the theme of "fiancée swapping", which dates back to the 13th century; notable earlier versions are found in Boccaccio's Decameron and Shakespeare's play Cymbeline.

[16] In a cafe, Ferrando and Guglielmo (two officers) express certainty that their fiancées (Dorabella and Fiordiligi, respectively) will be eternally faithful.

Ferrando and Guglielmo arrive, brokenhearted, and bid farewell (quintet: "Sento, o Dio, che questo piede è restio"—"I feel, oh God, that my foot is reluctant").

As the boat with the men sails off to sea, Alfonso and the sisters wish them safe travel (trio: "Soave sia il vento"—"May the wind be gentle").

The "Albanians" continue the attempt to win over the sisters' hearts, Guglielmo going so far as to point out all of his manly attributes (aria: "Non siate ritrosi"—"Don't be shy"), but to no avail.

Despina urges them to succumb to the "Albanians"' overtures (aria: "Una donna a quindici anni"—"A fifteen year old woman").

After she leaves, Dorabella confesses to Fiordiligi that she is tempted, and the two agree that a mere flirtation will do no harm and will help them pass the time while they wait for their lovers to return (duet: "Prenderò quel brunettino"—"I will take the dark haired one").

She puts up a token resistance, and soon she has given him a medallion (with Ferrando's portrait inside) in exchange for a heart-shaped locket (duet: "Il core vi dono"—"I give you my heart").

Guglielmo at first sympathises with Ferrando (aria: "Donne mie, la fate a tanti"—"My ladies, you do it to so many"), but then gloats, because his betrothed is faithful.