Italian composer who, with Domenico Cimarosa and Nicola Antonio Zingarelli, was one of the principal composers of opera buffa of his period.

Paer produced his first opera, Orphée et Euridice, in Parma in 1791 and achieved even more success in Venice the following year with Circe. From 1797 to 1802 he was musical director of the Kärntnertor Theatre in Vienna, where his most successful opera, Camilla, was produced in 1799. A C-minor funeral march in Achille (1801) impressed Beethoven and may have helped inspire the second movement of the Eroica symphony a few years later. Paer was in Dresden from 1802 to 1806, where his Leonore (1804) would prove a more direct influence on Beethoven. In 1805 Paer first crossed paths with Gioachino Rossini, who as a boy made his debut in Paer's Camilla. In 1807 he went to Paris, where he became chapelmaster to Napoleon, conducted at the Opéra-Comique, and (1812–27) directed the Théâtre Italien; he was accused during his later tenure there of intrigue against Rossini, who succeeded him as director. Paer's most successful opera of this period was Le Maître de chapelle (1821; The Chapelmaster). In addition to 43 operas he also composed religious and chamber music and secular cantatas.