Giuseppe Mattia Borgnis (Craveggia, 1701 - 1761) was an Italian painter and architect.
Born to a family of limited means, he apprenticed locally with a painter, from about 1710 to 1716. He then was sent to Bologna then Venice, where he was strongly influenced by the painters Giuseppe Maria Crespi and Giovanni Battista Piazzetta. By the age of 19, he returned to Craveggia. By the age of 25, he joined the studio of Andrea Dell'Angelo. Among Borgnis' pupils was Giuliano Da Parma and two of his sons, Giovanni (born 1728) and Pietro Maria (born 1743).
He was highly prolific in painting sacred subjects locally, including Villette, Baceno, Vocogno, Trontano Crana, Smeglio, (Mozzio) Coimo, Viganella, Montecrestese, Varzo, Trasquera, Bugliaga, Cattagna, Domodossola, Schieranco, Vocogno, Cimalmotto, Trontano, Sempione, Campo Valmaggia, Cevio Valmaggia, Prestinone, and Druogno. By 1752-1755; he tried to find work in Paris and London. He died in London, perhaps from a fall from a scaffold, about October 12, 1761. His children came to England to complete some of his works.
Among his masterworks are frescoes and canvases for both the parish church (1723-1727) and in the parish church of Santa Maria Maggiore. He painted for the Oratory of Gabbio in Malesco and the Oratory of the Madonna del Sasso di Orasso. He painted in the parish church of Campo di Valle Maggia (1748). In England, he painted for the palace of Sir Dashwood at West Wycombe, near London.