Giuseppe Caspar Mezzofanti (17 September 1774 – 15 March 1849) was an Italian cardinal and linguist. He was born and educated in Bologna. He completed his theological studies before he was old enough to be ordained and was ordained a Catholic priest in 1797. In the same year, he became professor of Arabic at the University of Bologna. He later lost this position for refusing to take the oath of allegiance to the Cisalpine Republic.

In 1803 he was appointed assistant librarian of the institute of Bologna, and soon afterwards was reinstated as professor of oriental languages and of Greek. The chair was suppressed by the viceroy in 1808, but again rehabilitated on the restoration of Pope Pius VII in 1814. Mezzofanti held this post until his removal from Bologna to Rome in 1831, as a member of the congregation de propaganda fide. In 1833, he succeeded Angelo Mai as Custodian-in-Chief of the Vatican Library, and in 1838 was made cardinal under the title of St. Onofrio al Gianicolo and director of studies in the Congregation.

Mezzofanti is well known for being a hyperpolyglot and it is believed that he spoke 38 languages and 50 dialects fluently. He could speak many other languages with less fluency.

See Russell, Life of the Cardinal Mezzofanti (London, 1857); A Bellesheim, Giuseppe Cardinal Mezzofanti (Würzburg, 1880).

This article incorporates text from the public domain 1911 Encyclopædia Britannica.