Nicola Francesco Haym was an Italian opera librettist, composer, theatre manager and performer, and numismatist. He is best remembered for adapting texts into libretti for the London operas of George Frideric Handel and Giovanni Bononcini. Libretti that he provided for Handel included those for Giulio Cesare, Ottone, Flavio, Tamerlano, Rodelinda, and several others; for Bononcini, he produced two, Calfurnia and Astianatte.

Haym was born in Rome. His career began as a cellist in Italy, and he arrived in London in 1701: he swiftly became master of the 2nd Duke of Bedford's chamber music. He wrote the libretto for Bononcini's Camilla, a seminal work of enormous success that did much to establish Italian opera in London. Later, when operas in London came to be performed entirely in Italian, rather than in a bilingual blend of English and Italian, Haym spent much time adapting both libretti and music for the many pasticcios that were staged at this time. In 1720 he was employed as a continuo cellist for the new Royal Academy of Music; in 1722, however, he became the Academy's Secretary for its final six seasons: he not only wrote the libretti but also took on the role of stage manager during this time. Prior to his death in London in 1729, he was planning to assist Handel and Heidegger construct a new Academy after the demise of the old one.