Duncan B. Hollis is Laura H. Carnell Professor of Law at Temple Law School and co-faculty director of Temple’s Institute for Law, Innovation & Technology (iLIT). His scholarship engages with issues of international law, interpretation, and cybersecurity, with a particular emphasis on treaties, norms, and other forms of international regulation.
Professor Hollis is a co-convenor of the Oxford Process on International Law Protections in Cyberspace and its accompanying Compendium. He is also an elected member of the American Law Institute, where he serves as an Adviser on its project to draft a Fourth Restatement on the Foreign Relations Law of the United States. From 2016-2020, he served as a member of the OAS’s Inter-American Juridical Committee, including as Rapporteur for projects on binding and non-binding agreements and improving the transparency of State views on international law’s application to cyberspace. Hollis has spent time as a Short-Term Visiting Fellow at the University of Oxford’s Jesus College, a Senior Fellow at Melbourne Law School, a Visiting Professor at LUISS Università Guido Carli, and a Visiting Scholar at the University of Pennsylvania’s Perry World House.
Professor Hollis’s books include The Oxford Guide to Treaties (OUP, 2nd ed., 2020), the first edition of which received the 2013 ASIL Certificate of Merit for high technical craftsmanship and utility to practicing lawyers; International Law (Aspen, 8th ed., 2023) (with Allen Weiner and Chimène Keitner); and Defending Democracies: Combatting Foreign Election Interference in a Digital Age (OUP, 2021) (with Jens Ohlin). His articles have appeared in various books and journals, including the American Journal of International Law, European Journal of International Law, Texas Law Review, Southern California Law Review, University of Pennsylvania Law Review, Harvard Journal of International Law, Vanderbilt Journal of Transnational Law, and Virginia Journal of International Law.
Professor Hollis received an A.B., summa cum laude, from Bowdoin College. In 1996, he completed a joint-degree program, receiving a Masters in International Law and Diplomacy from the Fletcher School at Tufts University and a Juris Doctor, summa cum laude, from Boston College Law School.
Following graduation, Professor Hollis worked for the International Department of Steptoe & Johnson LLP. In 1998, Professor Hollis joined the Office of the Legal Adviser at the U.S. Department of State, where he worked until joining the Temple faculty in 2004. During his tenure at the State Department, Professor Hollis served for several years as the attorney-adviser for treaty affairs, working on legal and constitutional issues associated with the negotiation, conclusion, and implementation of U.S. treaties. Professor Hollis’s practice has included international litigation before the International Court of Justice. In particular, he served as Counsel to the United States in the provisional measures phase of the Case Concerning Avena and Other Mexican Nationals (Mexico v. United States) and contributed to the U.S. presentation in the Oil Platforms Case (Iran v. United States), with the latter role earning him the State Department’s Superior Honor Award. Today, he continues to serve in various capacities, including as an expert witness, in international litigation. He also advises various international organizations and consults regularly, including advising the Microsoft Corporation on its Digital Diplomacy agenda.
Education
Research & Teaching Areas
Areas of Expertise
Selected Publications
Publications and Media Appearances SSRNLeadership
- Member, American Law Institute
- Co-Convenor, The Oxford Process on International Law Protections in Cyberspace (with Profs. Miles Jackson, Harold Koh, and Tsvetelina van Benthem)
Selected Conferences
- Presenter, The Prohibition on the Use of Force, Workshop: Advancing the Application of International Law in the Cyber Context in Africa, African Union and German Federal Foreign Office, Addis Ababa, Ethiopia, July 2026
- Presenter, New Challenges and New Concepts: Prepositioning and Civilian Critical Infrastructure and International Law, Public International Law Discussion Group, All Souls’ College, University of Oxford, February 2026
- Keynote Address, Aligned or Unaligned, Geopolitics and International Law in Cyberspace, Conference on International Cybersecurity, Leiden University, The Hague, November 2025
- Paper Presenter, LLMs and International Law, ISP Colloquium, Yale Law School, New Haven, Ct., September 2025
- Presenter, Delimiting Binding and Nonbinding Agreements for International Law, World Bank, Washington, D.C., July 2024
- Paper Presenter, The Original Meaning of Compacts, University of Chicago-University of Virginia Foreign Relations Law Workshop, University of Chicago Law School, Chicago, April 2024
- Keynote Speaker and Panelist, International Law – Novel Interventions, United Kingdom Advanced Command and Staff Course, Virtual Participant, November 2023.
- Lecturer, Treaties and Non-Legally Binding Instruments – Status and Treatment in International and Domestic Law, United Kingdom Foreign, Commonwealth & Development Office, Seminar Series, Virtual Discussion, May 2023
- Panelist, Enforcement Challenges in Cyberspace, Symposium on Reassessing Enforcement: Strengthening Compliance with International Law, Harvard Law School, Boston, MA, March 2023
- Presenter, Threatening Force in Cyberspace, Faculty Colloquium, Ohio State Moritz College of Law, Columbus, OH, March 2023
- Panelist, Suspension/Termination of Treaties in Armed Conflicts and Other Emergency Situations, 32nd Informal Meeting of Legal Advisers, United Nations General Assembly, New York, October 2022
- Lead Expert, Countermeasures in the Cyber Context, Tallinn Workshop on International Law and Cyber Operations, Republic of Estonia Ministries of Defense and Foreign Affairs/NATO CCD COE, Workshop, September 2022
- Paper Presenter, Do International Agreements have a Consent Problem? Consenting to International Law, Collège de France, Paris (June 2022)
- Treaty Expert and Presenter, UNCITRAL Working Group III (Investor-State Dispute Settlement Reform), Informal Meeting of Delegates, Hybrid Session, Vienna (June 2022).
- Lecturer, Mini-Series, Law of Treaties, U.N. Audiovisual Library of International Law, December 2021