Margaret Mahy (21 March 1936 – 23 July 2012) was a New Zealand author of children's and young adult books. Many of her story plots have strong supernatural elements but her writing concentrates on the themes of human relationships and growing up. She wrote more than 100 picture books, 40 novels and 20 collections of short stories. At her death she was one of thirty writers to win the biennial, international Hans Christian Andersen Medal for her "lasting contribution to children's literature".