John William O'Malley (June 11, 1927 – September 11, 2022) was an American academic, Catholic historian, and Jesuit priest. He was a University Professor at Georgetown University, housed in the Department of Theology and Religious Studies. O'Malley was a widely published expert on the religious history of Early Modern Europe, with specialities on the Council of Trent, the Second Vatican Council, and the First Vatican Council. Källa: Wikipedia (en)