Maria Vicien Milburn is an international judge and arbitrator, and former senior official of the United Nations. An Argentinian and Spanish national, she is a specialist in public international law with extensive dispute resolution experience in arbitration, conciliation and negotiation acquired through senior positions as General Counsel of UNESCO, Director of the General Legal Division of the United Nations, and Registrar of the United Nations Administrative Tribunal.

Ms Vicien Milburn currently acts as arbitrator in cases involving sovereign States, including under the auspices of the International Centre for Settlement of Investment Disputes (ICSID), the Permanent Court of Arbitration (PCA), and the International Chamber of Commerce (ICC). She is currently designated by the Kingdom of Spain to the ICSID Panel of Arbitrators (2026-2032). She served as Chair of the Sanctions Board of the World Bank and is the Alternate Chair of the Enforcement Appeals Committee of the Asian Development Bank. She sits as judge of the Administrative Tribunals of the European Space Agency (ESA), the European Bank for Reconstruction and Development (EBRD) and the International Monetary Fund (IMF). She formerly was a member of the Administrative Tribunal of the Inter-American Development Bank (IDB). She is a member of the list of panelists of the Dispute Settlement Body of the World Trade Organization (WTO).

During her thirty-five year career as an international lawyer at the United Nations and UNESCO, Ms Vicien Milburn provided legal advice on all issues relating to the operation of the two organizations worldwide. She oversaw all commercial contracting, directed the conduct of all litigation and arbitration, and advised on international treaties and conventions. Since retirement from the United Nations in 2014, Ms Vicien Milburn has continued to serve in multiple capacities as a special advisor to international organizations.

In her work as an arbitrator, she has adjudicated disputes in a wide array of sectors including telecommunications, real estate, procurement, and aviation. Trilingual in English, Spanish and French, she regularly acts in arbitrations in all three languages and involving parties in Europe, Latin America, the Middle East, and Africa. An active member of the arbitral community, Ms Vicien Milburn is an observer to UNCITRAL Working Groups II and III on international arbitration, a member of the ICC Arbitration Commission, and an advisor to the Board of the Arbitration Court of Madrid.

Ms Vicien Milburn is a graduate of the University of Buenos Aires Law School (Argentina) and received a Master in Laws from Columbia University. She is admitted to practice law in New York (non-active) and Buenos Aires.