Phoebe Okowa is Professor of Public International Law and Director of Graduate Studies at Queen Mary, University of London. In 2017, she has been appointed by Kenya as a Member of the Permanent Court of Arbitration, The Hague.

An Advocate of the High Court of Kenya, she has acted as counsel and consultant to governments and non-governmental organisations on questions of international law before domestic and international courts. Her notable cases as Counsel and Advocate before the International Court of Justice include Maritime Delimitation in the Indian Ocean (Somalia v. Kenya), Case Concerning Application of the Genocide Convention (Gambia v. Myanmar) and Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965, which involved a re-examination of the legal consequences of self-determination in the context of decolonisation (as a legal advisor to the Government of Kenya in connection with its intervention in the advisory proceedings).

Professor Okowa has also published over 30 articles, book chapters, shorter comments and reviews. She has written on a wide range of contemporary international law topics, including the interface between state responsibility and individual accountability for international crimes, unilateral and collective responses to protection of natural resources in conflict zones, and aspects of the protection of the environment.