Giacinto Diano or Diana was an Italian painter, active in Southern Italy in a style that mixes Rococo and Neoclassicism.

Giacinto was born in Pozzuoli, and died in Naples. He trained in the studio of Francesco De Mura, whose work would influence his early compositions. He worked briefly in Rome with Anton Raphael Mengs, before settling in Naples in 1752. Naples was at the time experiencing a period of great artistic and cultural splendor due to the presence of the enlightened Charles III of Spain. Nicknamed o Puzzulaniello or referred to as il Pozzolano, Giacinto succeeded in gaining within a short timespan a prominent place in the art scene of his time.

He became professor at Naples' Accademia del Disegno in 1773 but continued to achieve a prolific output. Gaetano Gigante was one of his pupils.