Jeffrey Gros FSC (7 January 1938 – 12 August 2013) was an American Catholic ecumenist and theologian. A member of the De La Salle Christian Brothers, Gros had served as a high school history teacher, university professor, associate director of the Secretariat for Ecumenical and Interreligious Affairs at the United States Conference of Catholic Bishops; director of Faith and Order for the National Council of Churches; and president of the Society for Pentecostal Studies. He is the author or editor of over 20 books, 310 articles, and an uncounted number of book reviews. He died of pancreatic cancer in Chicago, IL, on 12 August 2013 at the age of 75.