Professor Jan Klabbers

Professor Klabbers is the Director of the Lauterpacht Centre for International Law and Whewell Professor at the University of Cambridge, and a fellow of Murray Edwards College.


Previously Professor Klabbers was Professor of International Law at the University of Helsinki, where he was based since 1996, having previously taught at the University of Amsterdam. Professor Klabbers served for 20 years as Deputy Director of the Erik Castrén Institute of International Law and Human Rights and, from 2006 to 2011, as Director of the Academy of Finland Centre of Excellence in Global Governance Research. Between 2013 and 2018 he held the Academy of Finland Martti Ahtisaari Chair. He has also served as a member of the Executive Council of the European Society of International Law and as a Panellist for the European Research Council and the Swiss Network for International Studies. He has received several teaching awards at the University of Helsinki and was inducted into the Finnish Academy of Sciences and Letters in 2014. He is one of the founding editors of the 'International Organizations Law Review', and was its book review editor for seventeen years. Since 2025 he serves as co-editor in chief of the British Yearbook of International Law. He has held invited visiting positions at a number of institutions of higher learning, including New York University, the Graduate Institute, and LUISS Guido Carli.

Professor Klabbers is widely regarded as one of the world’s leading experts in the law of treaties and the law of international organisations. His publications include 'International Law' (Cambridge University Press, 2023, 4th edition; the fifth edition is in press), 'Virtue in Global Governance: Judgment and Discretion' (Cambridge University Press, 2022), 'Treaty Conflict and the European Union' (Cambridge University Press, 2009), 'An Introduction to International Organizations Law' (Cambridge University Press, 2022, 4th edition) and 'The Concept of Treaty in International Law' (Kluwer, 1996). Professor Klabbers recently completed a research project, funded by a €2.5 million European Research Council grant, on relations between intergovernmental organisations and the private sector. This project has spawned a number of articles and several volumes, including 'International Organizations Engaging the World' (Cambridge University Press, 2025), with another volume, 'International Organizations Facilitating Markets', in the pipeline.