Margaret Ellen Mary O'Flynn (25 January 1920 – 22 September 2014), known professionally as Margaret Foley, was a British gynaecologist and pioneer of contraception services for women. She dedicated most of her career to the improvement of women's health in Portsmouth and south east Hampshire, which witnessed a flourishing range of facilities and services in family planning, women's sexual health, and the management of the menopause, as a result of her determination.