Il pirata (The Pirate) is an opera in two acts by Vincenzo Bellini with an Italian libretto by Felice Romani, which was based on a three-act mélodrame from 1826: Bertram, ou le Pirate (Bertram, or The Pirate) by Charles Nodier and Isidore Justin Séverin Taylor. This play was itself based upon a French translation of the five-act verse tragedy Bertram, or The Castle of St. Aldobrand by Charles Maturin which appeared in London in 1816.

The original play has been compared with Bellini's opera and the influence of Il pirata on Gaetano Donizetti's Lucia di Lammermoor has been noted. Also, Bellini's recycling of his own music in this opera has been analyzed, as well as his utilizing "a more self-consciously innovative compositional style" and participating more in work on the libretto, as compared with prior efforts where he was more deferential to the librettists chosen by the Naples opera management and the corresponding texts. In addition, 19th-century commentary refers to the musical influence of Il pirata on the early Richard Wagner opera Das Liebesverbot.

Bellini spent 1827 to 1833 mostly in Milan, never holding any official position within an opera company and living solely from the income produced from his compositions, for which he was able to ask higher than usual fees.

Upon his arrival, he met Antonio Villa of La Scala and composer Saverio Mercadante whose new opera, Il Montanaro was in rehearsal. The latter introduced him to Francesco and Marianna Pollini (an older couple, the husband a retired professor of piano, the wife a better-than-amateur musician) who immediately took the young man under their wing.

In addition, Bellini was introduced to the librettist Felice Romani, who proposed the subject of the composer's first project, Il pirata, to which the young man willingly agreed, especially after he realised that the story "provided several passionate and dramatic situations.. [and]..that such Romantic characters were then an innovation on the operatic stage." From that time forward, there began a strong professional relationship with Romani; he became Bellini's primary creative partner, providing the librettos for six of Bellini's operas which followed, the result being that "no other Italian opera composer of the time showed such an attachment to a single librettist". Although Romani was known to treat composers poorly, he evidently had great respect for Bellini, even acceding to his requests for revisions. For his part, Bellini admired "the sonorous and elegance of the poet's verses"

The collaboration began in May 1827 and, by August, the music was being written. By then, the composer was aware that he was to write music for his favourite tenor Giovanni Battista Rubini and the soprano was to be Henriette Méric-Lalande. Both singers had starred in Bianca e Fernando in the original 1826 production. The strong cast also included Antonio Tamburini, a major bass-baritone of the time.

But rehearsals did not progress without some difficulties, as both Weinstock and Galatopoulos recount: it appears that Bellini found Rubini, while singing beautifully, to be lacking expressiveness: he was urged to "throw yourself with all your soul into the character you are representing" and to use [your] body, "to accompany your singing with gestures", as well as to act with [your] voice. But it seems that Bellini's exhortations bore fruit, based on his own account of the audience's reactions to the first performance, as well as the reaction of Milan's Gazzetta privilegiata of 2 December which noted that this opera "introduced us to Rubini's dual personality as a singer and actor". The reviewer continued to declare that this duality had never been expressed in other operas in which he had performed.

The premiere, given on 27 October 1827, was "an immediate and then an increasing, success. By Sunday, December 2, when the season ended, it had been sung to fifteen full houses". For Rubini, "it marked the defining performance for the tenor", and the newspaper reviews which followed all agreed with the composer's own assessment.