María José Alarcón Santillán is an international lawyer based in London, specializing in public international law, state responsibility, climate change law and investment arbitration. She is Regional Co-leader for International Courts and Tribunals at the Columbia Sabin Center for Climate Change Law and serves as Counsel for the IUCN in the Advisory Opinion for Climate Change before the International Court of Justice.

María is an S.J.D candidate at GW Law. She holds a Master of Laws from Duke Law, a dual Master of Laws in corporate and EU law from IE University, a Bachelor of International Law from The University of Navarra and a Bachelor of Laws from Universidad Hemisferios. She holds bar admissions in New York, Spain, and Ecuador, and is a Solicitor of England and Wales.

María academic engagements include contributions as Associate Professor of International Environmental Law and research roles at Leiden University, Duke University, assistant editor for the Kluwer Arbitration Blog, and research for the ASIL Task Force on Investor-State Dispute Settlement (ISDS) and Climate Change.

María has advised states in disputes before ICSID, ITLOS, the PCA, and the ICJ and has published extensively on investment arbitration, investment treaty reform and climate litigation. Her work blends practice and academia to address legal challenges at the intersection of international dispute resolution, sustainability and human rights. She is committed to advancing legal scholarship and policy in support of global climate justice.