Peter De Mey

Peter De Mey is a full Professor of Roman-Catholic Ecclesiology and Ecumenism at the Research Unit Systematic Theology and the Study of Religions, Faculty of Theology and Religious Studies, KU Leuven. He is affiliated with the Centre for Ecumenical Research, the Centre for the Study of the Second Vatican Council, and the Louvain Center for Eastern and Oriental Christianity (LOCEOC). He has guided 25 successful doctoral dissertations and led numerous research projects.

He served as founding chair of the Vatican II Studies group (2012–2016) at the American Academy of Religion, and as secretary/president of Societas Oecumenica (2004–2010). He actively participates in the Ecclesiological Investigations Network and the Peter & Paul Seminar. Since 2005, he has been on the Board of the National Commission for Ecumenism (president since 2010) and co-president of the Dialogue Commission with the United Protestant Church in Belgium.

Research Interests: His work focuses on pre- and post-Vatican II ecumenical developments, the redaction history of key Vatican II documents (e.g., Lumen Gentium, Unitatis Redintegratio), and Eastern Christian theology. He explores themes like synodality, lay co-responsibility, and intercommunion policies.

Recent Publications: Recent works analyze the role of Russian Orthodox theologians in Chevetogne dialogues, the evolution of lay theology in 20th-century Catholicism, and the impact of Vatican II on Peruvian episcopal practices. His articles address theological responses to the sexual abuse crisis and the papacy’s evolving role in a synodal church.

Grants & Leadership: Secured multiple grants, including a sabbatical for a Vatican II commentary. His advisory role has shaped 25 doctoral theses, reflecting his mentorship in ecumenical and historical theology.

Labs/Teams: Leads projects at LOCEOC, the Centre for Ecumenical Research, and collaborates internationally on Eastern Christian studies and synodal church models.