Mary Isobel Downer, Lady Downer (13 December 1924 – 14 October 2014) was a prominent South Australian patron, wife of federal MP and high commissioner Sir Alexander "Alick" Downer, and mother of Australian Foreign Minister and high commissioner Alexander Downer.Mary Gosse and her four brothers were raised in Parkside, Adelaide where she was educated at Seymour College, a private Uniting Church school for girls.