Mortimer "Tim" Sellers is Regents Professor of the University System of Maryland and Director of the University of Baltimore Center for International and Comparative Law. Sellers has written numerous books and articles on international law, constitutional law, the philosophy of law, comparative law, and legal history. He is the co-editor (with Mark Agrast) of the Cambridge University Press book series ASIL Studies in International Legal Theory, and co-editor (with David Gerber) of the Cambridge series ASCL Studies in Comparative Law . He is co-editor (with Stephan Kirste) of the IVR Encyclopedia of the Philosophy of Law.

In addition to his academic work, Sellers has practised law in Philadelphia and Washington, served as clerk to the Hon. James Hunter III of the United States Court of Appeals for the Third Circuit, and studied as a Rhodes Scholar and Frank Knox Fellow at University College, Oxford. He has been a visitor at Oxford University, Cambridge University, Erasmus University Rotterdam, the Academy of International Law in The Hague, and Georgetown University Law Center.

Sellers is the President of IVR, the International Association for the Philosophy of Law and Social Philosophy and an associate member of the International Academy of Comparative Law.  He is a member of the Middle Temple and is admitted to practice before the District of Columbia, Maryland, New Jersey, Pennsylvania, and the United States Supreme Court bars.