Mary Montagu may refer to:Lady Mary Faith Montagu (1911–1983), daughter of the 9th Earl of Sandwich
Lady Mary Wortley Montagu (1689–1762), English writer
Mary Montagu Douglas Scott, Duchess of Buccleuch (1900–1993), British duchess
Mary Montagu, Duchess of Montagu (1689–1751), formerly Lady Mary Churchill, wife of John Montagu, 2nd Duke of Montagu
Mary Montagu, Duchess of Montagu (1711–1775), daughter of the above, wife of George Brudenelllater Montagu, 4th Earl of Cardigan, and later Duchess of Montagu
Mary Stuart, Countess of Bute (1718–1794), wife of John Stuart, 3rd Earl Stuart