Helen Dick Megaw was born in Dublin, the elder daughter of Robert Dick Megaw and Annie McElderry. She was educated in Dublin and at Roedean School and Queen's University, Belfast, before coming to Girton College to study Natural Sciences in 1926. She was awarded a Cambridge PhD in 1934. Her research and teaching in the ensuing years briefly comprise the following: Research on crystallography in Vienna 1934-35; Research on low temperatures at the Clarendon Laboratory in Oxford 1935-36; Assistant Mistress at Bedford High School 1936-39 and Bradford Girls' Grammar School 1939-43; X-Ray Crystallographer at the Material Research Laboratory, Philips Lamps Ltd, Mitcham, Surrey, 1943-35; Assistant Director of Research at the Crystallographic Laboratory, Birkbeck College, London 1945-46. In 1946 she returned to Cambridge as a Staff Fellow, Director of Studies in Natural Sciences and Lecturer in Physics at Girton College and an Assistant in Research in Crystallography at the Cavendish Laboratory, where she pursued for many years her investigations into the crystal structure of felspars and ferroelectrics. In 1951, Helen Megaw was a scientific consultant to the 'Festival Pattern Group', which supplied crystallographic patterns as a basis for textiles, ceramics, decorative paper and furnishings as part of the Festival of Britain. Helen Megaw was actively involved in the Third Foundation Association, which in 1954 founded New Hall [now Murray Edwards College], Cambridge's third college for women. She was also a member of the New Hall Association, which governed the college until it gained full collegiate status in 1972. In addition to many scientific articles, Helen Megaw published, in 1957, a book entitled 'Ferroelectricity in Crystals', the first of its kind. A second book, 'Crystal Structures: a Working Approach' was published in 1973. Honours awarded to Helen Megaw included the Roebling Medal of the Mineralogical Society of America in 1989 (she was the first woman to receive the medal) and an honorary degree from Queen's University, Belfast in 2000. Megaw Island in the Antarctic was named after her in honour of her early work on the crystallographic structure of ice. Helen Megaw retired in 1972. She died at Ballycastle, Co Antrim, on 26 February 2002.