Il Bellerofonte is an 18th-century Italian opera in three acts by the Czech composer Josef Mysliveček. It conforms to the serious type (opera seria) that was typically set in the distant past. The libretto, based on the Greek legend of Bellerophon, was written by Giuseppe Bonecchi. The work was dedicated to King Ferdinand I of the Two Sicilies and was first performed at the Teatro San Carlo in Naples on 20 January 1767, the birthday of his father, King Charles III of Spain. The cast featured two stellar singers of the time, Caterina Gabrielli and Anton Raaff, in the leading roles. The opera was only the composer's second one, and the first that permitted him the opportunity to write music for first-rate vocal artists. The production was highly successful, indeed responsible for a meteoric rise in his reputation as an operatic composer. From the time of the premiere of Bellerofonte until his death in 1781, Mysliveček succeeded in having more new opere serie brought into production than any other composer in Europe. During the same time span, he also had more new operas staged at the Teatro San Carlo in Naples than any other composer.

The subject, chosen by the management of the Teatro San Carlo, was unusual among Mysliveček's operas. Historical settings, rather than mythological ones, were customary for serious operas in Italy of the 1760s, unless elements from the French tragédie lyrique were included to create a Franco-Italian fusion. In this case, the inclusion of choruses and programmatic musical effects mark it as moderately influenced by French operatic traditions aside from the choice of mythological subject matter.

As in many 18th-century productions at the Teatro San Carlo, the first performance of Il Bellerofonte included separate ballets, none of the music for which was composed by Mysliveček or used in subsequent performances of the opera. The premiere production included a ballet at the end of Act I, Un bassà turco (A Turkish Pasha), and one at the end of Act II, Pantomimo tra Pulcinella, Arlecchino e Coviello (Pantomime between Pulcinella, Harlequin and Coviello). The opera was also preceded by a festive dance while a cantata was sung in honor of King Ferdinand I (also composed by Mysliveček). The ballets were choreographed by their leading dancer, Gennaro Magri. The opera was revived in Siena in spring of 1767 and Prague in carnival of 1768. A notation on a copy of the score in Paris indicates that it was revived at the San Carlo in 1769, however no librettos survive to confirm this.

Il Bellerofonte features many arias with elaborate vocal virtuosity of the type favored by Italian audiences of the 1760s. The ones most widely admired were "Splende così talora" from Act I, scene 2; "Giusti Dei" from Act I, scene 3; "Ch’io mai capace" from Act II, scene 5; and "Palesar vorrei col pianto" from Act II, scene 11. These arias were copied in aria collections throughout Italy, but they were even more widely disseminated in Bohemia in the collections of sacred institutions that substituted Latin texts for the original Italian. In this form, arias from Il Bellerofonte continued to circulate in central Europe well into the 19th century.