Katherine (Kay) MacDonald (1931 – 31 August, 2018) was a Canadian religious figure who, at the time of her appointment as president of the International Union of Superiors General, was the highest ranking woman in the Catholic Church. Her career started at a small Catholic Academy in Saskatchewan, Canada and led her to a variety of senior positions across Canada, in Rome, and in Israel. MacDonald focused her career on fighting antisemitism in the Catholic Church and improving relationships between Christian and Jewish populations. MacDonald's life and career has been documented by the National Film Board of Canada in a 2000 documentary co-production between the NFB and Four Square Productions Canada Ltd.