Kate Mackintosh is the Executive Director of the UCLA Law Promise Institute Europe, based in The Netherlands. She served as the inaugural Executive Director of the Promise Institute for Human Rights from August 2018 to July 2023.

Mackintosh has worked in the fields of human rights, international criminal justice, and the protection of civilians for three decades. She was involved in the development of international criminal law in its fledgling years and contributed to defining many elements of this new area of law, such as the elements of rape as an international crime, the definition of protected persons, and the scope of complicity for international crimes.

She has held multiple roles at international criminal tribunals, working as a lawyer with the judges; prosecution appeals counsel; co-counsel for the defense and finally as an administrator, responsible as Deputy Registrar for the International Criminal Tribunal for the former Yugoslavia’s court operations, witness protection and support services, legal aid scheme, detention facility, communications and outreach, languages services and archives.

For eight years, Mackintosh worked with Doctors without Borders, providing legal and policy advice to operations in over 30 countries around the world, and leading advocacy in support of some of the world’s most vulnerable populations. During, and building on, this experience, she developed a body of work around the practical application of IHL and humanitarian principles to contemporary challenges, ranging from critiques of the impact of counter-terrorism law and policy on humanitarian action to the scope of humanitarian actors’ legal obligation to testify and the legitimacy of humanitarian protection.

Mackintosh was part of post conflict human rights field operations in Rwanda – working to rebuild the justice system after the genocide – and Bosnia, where she collaborated with Bosnian lawyers on strategies to use the courts to support economic and social rights. She has lectured and authored numerous articles and reports on the principles of humanitarian action, international criminal justice and the protection of civilians.

In summer 2020, Mackintosh was appointed deputy chair of the Independent Expert Panel for the Legal Definition of Ecocide, which issued its draft proposal in June 2021. In January 2024, she was appointed to the International Council of Experts on the Investigation of Crimes Committed in Armed Conflict in Ukraine. In November 2024 she was appointed to the Advisory Group for the International Criminal Court Prosecutor’s Policy on Environmental Crimes. Mackintosh represented the State of Palestine at the International Court of Justice in the climate change proceedings in December 2024. The interrelationship of the protection of the environment with human rights and international criminal justice is a current focus of her work.