The characteristic aim of Margaret O’Gara’s 37 years of work as a theologian was to foster dialogue among Christians for the sake of overcoming divisions between the churches. Besides her teaching, research, writing, and extensive public lecturing, she was a member of official ecumenical dialogues in Canada, the United States, and at the international level. She also served as president of the North American Academy of Ecumenists and the Catholic Theological Society of America. Her effectiveness in all these arenas came from a combination of her scholarly rigor, her ability to listen sympathetically, her uncommon energy, and her contagious delight at the growth of mutual understanding and friendship. Margaret was also a deeply loved board member of the Collegeville Institute. Margaret died on August 16, 2012, and is survived by her husband, Michael Vertin.