Harold Hongju Koh is a lawyer and legal scholar who has twice served as the senior Legal Adviser to the Department of State, during the Obama and Biden administrations. Koh has served as a foreign affairs policymaker and lawyer under four presidents over the last five decades, including the Department of State during the Clinton administration as Assistant Secretary of State for Democracy, Human Rights, and Labor and the Department of Justice Office of Legal Counsel in the Reagan Administration. In academia, he has long served as a professor at Yale Law School, and for five years as its dean.

Koh is the author of several books, among them The National Security Constitution In the 21st Century (Yale, 2024); The National Security Constitution: Sharing Power after the Iran-Contra Affair (Yale,1990); Transnational Legal Problems (with Henry Steiner and Detlev Vagts; Foundation Press, 1994); Deliberative Democracy and Human Rights (with Ronald Slye, Yale, 1999); Transnational Litigation in United States Courts (Foundation Press, 2008), and The Trump Administration and International Law (Oxford 2018). A prominent advocate of human rights and civil rights, Koh has written over 200 law review articles and has appeared frequently before US courts, frequently testified before Congress, and since 2016, has represented Ukraine before international courts, including the international Court of Justice.

Among his many awards, medals, and honorary degrees are the 2024 Robert A. Katzmann Burton Award for Academic Excellence, and awards from the American Bar Association and Columbia and Duke Law Schools for his lifetime achievements in international law.