Alzira is an opera in a prologue and two acts by Giuseppe Verdi to an Italian libretto by Salvadore Cammarano, based on the play Alzire, ou les Américains by Voltaire.

The first performance was at the Teatro San Carlo, Naples, on 12 August 1845. The contemporary reviews were mixed, and the first run of the opera received only four further performances.

The opening performance received a complimentary note of approval in Naples' Gazzetta Musicale: "Beauties so delicately contrived that the ear can hardly take them in". However, the general reaction in Naples was not positive, even worse when Alzira was staged in Rome in November 1845 and, worse still, after the 1846 presentations at La Scala, resulting in the worst press that the composer had seen since the failure of Un giorno di regno in 1840. It was staged in Ferrara as part of the Spring 1847 carnivale season , after which it disappeared from the repertory.

Prior to 1940, the opera was not performed very often; however, there was a 1938 concert performance in Berlin with Elisabeth Schwarzkopf. Other recordings show that there has been a steady flow of presentations, many only in concert form, especially since 2000. Postwar stagings include those given by the Rome Opera in February 1967 (with Cornell MacNeil as Gusmano). According to Budden this "proved that the score in genuinely alive" and he concludes by noting that it is "not downright bad" and that "no Verdi opera is totally negligible".

It was not until January 1968 that it was first given in the US: a concert version was given in Carnegie Hall, New York on 17 January 1968 with Louis Quilico. Its UK premiere took place on 10 February 1970 at the Collegiate Theatre in London. Also, in the 1970s, the Orchestra and Chorus of RAI in Turin under Maurizio Rinaldi gave a radio performance which was broadcast.

In February 1981, it was staged by the Teatro Regio di Parma and in July 1996, a performance was given at the Royal Opera House in London

In March / April 1998 it was given in the Stadttheater in Passau; it was included in 2000 in the Sarasota Opera's "Verdi Cycle"; and it was revived at the Teatro Regio di Parma in May/June 2002, with Vladimir Chernov. Periodically, between January and June 2010, it was presented by the Theater St Gallen in Switzerland, with Paolo Gavanelli appearing in some performances.

Other presentations, in concert form, have appeared: in 1999 in the Victoria Hall, Geneva, in June / July; in 2003 in Carnegie Hall, New York on 31 January; and in 2012 in Toblach, South Tyrol in Northern Italy under Gustav Kuhn, conducting the Orchestra Haydn di Bolzano e Trento.

In London in June 2013, the Chelsea Opera Group presented a concert version of the opera, with Majella Cullagh in the title role.