Mary Adelaide
Mary Adelaide may refer to:
- Mary Adelaide Dickey, American vaudeville performer
- Mary Adelaide Eden Phillpotts, birth name of Adelaide Phillpotts, English novelist, poet, and playwright
- Mary Adelaide Hare, English teacher of deaf children, and suffragist
- Mary Adelaide Nutting, Canadian nurse, educator, and pioneer
- Mary Adelaide Virginia Thomasina Eupatoria FitzPatrick, birth name of Patsy Cornwallis-West, Irish aristocrat and mistress of King Edward VII
- Mary Adelaide Walker, 19th-century English writer
- Princess Mary Adelaide of Cambridge, later Duchess of Teck, by marriage
- Princess Marie Adélaïde of France, daughter of Louis XV of France
- Marie-Adélaïde, Grand Duchess of Luxembourg, Sovereign of Luxembourg
- Princess Marie-Adélaïde of Savoy, mother of Louis XV of France