Il corsaro (The Corsair) is an opera in three acts by Giuseppe Verdi, from a libretto by Francesco Maria Piave, based on Lord Byron's poem The Corsair. The first performance was given at the Teatro Grande in Trieste on 25 October 1848.

The composer expressed interest in Byron's poem The Corsaire as early as 1844, but it was several years before he got around to composing the opera, working with a libretto by Francesco Maria Piave. Meanwhile, Verdi was caught up in a squabble between two publishers doing battle over his work. Il Corsaro was written for the publisher who lost that battle — at least in the composer's eyes — and Verdi may have been anxious to get past it. In any case, when he finished the score in 1848, and turned it over to the publisher, he apparently had no idea where or when it would be produced. When it premiered at the Teatro Grande (now the Teatro Lirico Giuseppe Verdi) in Trieste later that year, Verdi did not attend the first performance. He may have known exactly what he was doing. As it turns out, the opera was poorly received — an unusual occurrence for Verdi. It quickly fell out of favor.