Maria Paternò Arezzo (December 11, 1869, Ragusa Ibla, Sicily — December 28, 1908, Messina), Princess of Castellaci, was an Italian noblewoman and philanthropist who is renowned for her charity bequest to build a hospital for the poor in her city of birth. She was the daughter of Giuseppe Maria Alvaro Paternò, the 5th Prince of Sperlinga and 13th Baron of Manganelli, and of Vincenzina Arezzo of the barons of Donnafugata.