(1689 - 17 August 1767) was an Italian painter of the late-Baroque or Roccoco period, active mainly in the Veneto but also in Dresden and Munich.
His earliest training was in his native town of Belluno with Antonio Lazzarini, then moved to Venice, to the studio of Gregorio Lazzarini and later that of Sebastiano Ricci. He was seven years older, but otherwise his career was contemporary with the Lazzarini and Ricci fellow-pupil, Giovanni Battista Tiepolo.
Between 1710-1720, he painted a group of eight pictures that included the Mary Magdalene for the church of San Stefano in Belluno, and Entry into Jerusalem for San Teodoro in Venice. He also painted three frescoes on the Life of Saint Helena in the Scuola del Vin next to the church of San Silvestro. Dizianies celerity and technical assurance are evident preparatory oil sketches, with color applied in rapid and spirited strokes.
He was also working as a scenery painter for the theater and opera in Venice, Munich (1717), and later in Dresden, working with Alessandro Mauro. Diziani was invited to Rome by Cardinal Ottoboni in 1726, to paint a emagnificent decoration for the church of San Lorenzo in Damaso. The decoration is now known only through an engraving by Claude Vasconi.
The Sala dei Pastelli in Ca' Rezzonico has an sotto in su allegorical ceiling fresco presenting Triumph of Poetry (Poetry surrounded by Painting, Architecture, Music and Sculpture).