Semiramide is an opera in two acts by Gioachino Rossini. The libretto by Gaetano Rossi is based on Voltaire's tragedy Semiramis, which in turn was based on the legend of Semiramis of Assyria. The opera was first performed at La Fenice in Venice on 3 February 1823.

Semiramide was Rossini's final Italian opera and according to Richard Osborne, "could well be dubbed Tancredi Revisited". As in Tancredi, Rossi's libretto was based on a Voltaire tragedy. The music took the form of a return to vocal traditions of Rossini's youth, and was a melodrama in which he "recreated the baroque tradition of decorative singing with unparalleled skill". The ensemble-scenes (particularly the duos between Arsace and Semiramide) and choruses are of a high order, as is the orchestral writing, which makes full use of a large pit.

After this splendid work, one of his finest in the genre, Rossini turned his back on Italy and moved to Paris. Apart from Il viaggio a Reims, which is still in Italian, his last operas were either original compositions in French or extensively reworked adaptations into French of earlier Italian operas.

Musicologist Rodolfo Celletti sums up the importance of Semiramide by stating that it "was the last opera of the great Baroque tradition: the most beautiful, the most imaginative, possibly the most complete; but also, irremediably, the last."