Sergey Vasiliev is a full professor of international law at the Department of Public Law. His main fields of expertise within public international law include international criminal law, international humanitarian law, human rights, procedure before international courts and tribunals, and institutional and governance aspects of international adjudication. He has also taught comparative (criminal) law, transnational criminal law, and European Union criminal law.

Vasiliev's research interests cover the critical and comparative approaches to the history and methodology of international law; the international rule of law and the relationship between states and international courts; accountability for core international crimes; and the right to resist and transitional justice after conflict and periods of oppression.

Previously he worked as an associate professor (2020-24) and an assistant professor (2019-20) at the section of criminal law of the Law Faculty, University of Amsterdam, where he also served as the founding Director of the Amsterdam Center of Criminal Justice and the academic director of the two-track LL.M International Criminal Law.

His prior academic appointments include an assistant professorship in public international law at the Grotius Center for International Legal Studies, Faculty of Law, Leiden University (2016-19) and postdoctoral researcher positions on pluralism/harmonization in international criminal law (Law Faculty, Vrije Universiteit Amsterdam) and on general principles and rules of international criminal procedure (University of Amsterdam).

Vasiliev defended his PhD in international criminal procedure at the University of Amsterdam in 2014 (cum laude).