For the 1942 Italian film, La donna mobile, see The Lady Is Fickle.
"La donna è mobile" (Italian pronunciation The woman is fickle) is the Duke of Mantua's canzone from the beginning of act 3 of Giuseppe Verdi's opera Rigoletto (1851). The inherent irony is that the Duke, a callous playboy, is the one who is mobile ("inconstant"). Its reprise towards the end of the opera is chilling, as Rigoletto realizes from the sound of the Duke's lively voice coming from within the tavern (offstage), that the body in the sack over which he has grimly triumphed is not that of the Duke after all: Rigoletto had paid Sparafucile, an assassin, to kill the Duke but Sparafucile deceived him by killing Gilda, Rigoletto's beloved daughter, instead.

The canzone is famous as a showcase for tenors. Raffaele Mirate's performance of the bravura aria at the opera's 1851 premiere was hailed as the highlight of the evening. Before its first public performance (in Venice), it was rehearsed under tight secrecy:[1] a necessary precaution, because it proved to be catchy and soon after its first public performance every gondolier in Venice was singing it.