Giuseppe Siboni (27 January 1780 – 28 March 1839) was an Italian operatic tenor, opera director, choir conductor, and voice teacher. He began his career in his native country in 1797 and actively performed in major Italian opera houses up through 1818. From 1806 to 1809 he performed successfully in London, and from 1810 to 1814 he was active in Vienna, where he enjoyed the friendship of Ludwig van Beethoven. He played a critical role in Danish musical life from 1819 until his death in 1839. In 1819 he joined the Royal Danish Theatre in Copenhagen, where he worked first as a singer and later as director of the opera chorus and head director. In 1827 he founded the Royal Conservatory of Music in Copenhagen. He was married three times during his life, including his second marriage to the sister of poet Franz von Schober. His third marriage produced a son, the composer and pianist Erik Siboni (1828–1892).
Born in Forlì, Siboni studied singing in his native city with castrato Sebastiano Folicaldi. He made his professional opera debut in 1797 at the age of 17 in Florence. Over the next several years he sang with various Italian opera troupes, making appearances in Genoa, Milan, and Prague among other cities. In Prague he married Louise Veith, the daughter of a local banker. He made his debut at La Scala on 26 December 1805 as Abenamet in the world premiere of Giuseppe Nicolini's Abenamet e Zoraide. He returned there the following year to sing the role of Marco Orazio in Domenico Cimarosa's Gli Orazi e i Curiazi.
From 1806 to 1809, Siboni sang in three seasons at the King's Theatre in London. His first critical success there was as Ruggero in Ferdinando Paër's Il principe di Taranto on 23 December 1806. In the 1809–10 season he was once again at La Scala, where he had a particular triumph as the title hero in the world premiere of Simon Mayr's Raoul di Crequi on 26 December 1809. From 1810 to 1814 he was active in Vienna, where he notably performed in the world premiere of Ludwig van Beethoven's Tremate, empi tremate on 27 February 1814. He was much admired at the Vienna Hofoper as Licinio in Gaspare Spontini's La vestale and in several operas by Paer. In 1813 he performed as a guest artist in Prague.