Mary Milligan was an American theologian, a university administrator, and a member of the Religious of the Sacred Heart of Mary (RSHM) who served as the tenth general superior of the Institute of the RSHM (1980–1985). She was the first general superior of that religious order who was born in the United States. In 1987, she was appointed by the Vatican as special secretary to the International Synod of Bishops on the Laity as one of three U.S. experts. While undertaking that task, she lobbied for a stronger role for women within the Catholic Church. She served Loyola Marymount University as a professor, as provost, and subsequently as Dean of Bellarmine College of Liberal Arts. She went on to serve on the board of St. John's Seminary in Camarillo, California, and taught theology to seminarians.