Philippe Portier was previously a professor of political science at the University of Rennes I. Since 2007, he has been director of studies at the Ecole Pratique des Hautes Etudes (PSL), where he holds the chair of "History and Sociology of Secularism". He is also a professor at Sciences Po Paris. Former director of the Groupe Sociétés, Religions, Laïcités, a research center of the Ecole Pratique des Hautes Etudes and the Centre National de la Recherche Scientifique (from 2008 to 2018), and former First Vice President of the EPHE, he is now co-director of the Observatoire International du Religieux (Sciences Po-EPHE). He is a member of many scientific committees. He is the head of two important series of two eminent publishers : The Presses Universitaires de Rennes and the Classiques Garnier.
His work focuses on secular regimes, on the mutations of religion in Western societies, and more globally on the relationship between democracy and religion. His most recent works include Métamorphoses catholiques, Acteurs, enjeux et mobilisations autour du mariage pour tous, Paris, Editions de la Maison des Sciences de l'Homme, 2015 (with Céline Béraud), L'Etat et les religions en France. Une sociologie historique de la laïcité, Rennes, PUR, 2016, Politique et religion. L'enjeu mondial, Paris, Presses de Sciences Po, 2017 (ed. with Alain Dieckhoff), Cent ans de construction sociale. Une histoire de la Confédération française des travailleurs chrétiens, Paris, Flammarion, 2019, La sécularisation en question. Religion et laïcités au prisme des sciences sociales, Paris, Les Classiques Garnier, 2019 (ed. with Jean Baubérot and Jean-Paul Willaime), Le religieux dans les conflits armés contemporains, Paris, Les Classiques Garnier, 2019 (ed. with Frédéric Ramel), La religion dans la France contemporaine, Entre sécularisation et recomposition, Paris, Armand Colin, 2021 (with Jean-Paul Willaime) ; Religion and secularism in contemporary France (ed. with Jean-Paul Willaime) London-New Dehli, Routledge, 2022.