Donald Sydney Smith OBE (27 July 1920 – 1 December 1998) was an Australian operatic tenor. His voice had a bright Italianate quality, which could match in size, carrying power and tonal allure the voices of most sopranos and mezzos. He attracted a fiercely loyal public following, and many Australians who had no prior experience of opera became opera lovers through Smith's work. His performances were regularly sold out with The Australian Opera at the Sydney Opera House.