Carlo Giuseppe Ratti (1737–1795) was an Italian art biographer and painter of the late-Baroque period. He was a pupil of the painter Giovanni Agostino Ratti. Born in Savona, he moved to Rome where he befriended Anton Raphael Mengs and Pompeo Batoni. He died in Genoa, where he labored for many years.
He added to Raffaele Soprani’s history of Genoese painters: Vite de' pittori, scultori ed architetti genovesi first published in 1769 in Genoa. He painted an Annunciation for the church of Santa Maria delle Vigne in Genoa. He also published A Life of Rafael Mengs, and Notices of Correggio. He corresponded with Luigi Lanzi, providing information regarding the artworks and painters in Liguria for Lanzi's Storia Pittorica dell'Italia. He was knighted by Pope Pius VI and made director of the Accademia Ligustica di Belle Arti.
One of his pupils was the portraitist Raimondo Ghelli.[1]