Janina Dill is the John G. Winant Professor of U.S. Foreign Policy at the Department of Politics and International Relations (DPIR) of the University of Oxford. She is also a Professorial Fellow at Nuffield College and Co-Director of the Oxford Institute for Ethics, Law, and Armed Conflict (ELAC).

Her research concerns international law and ethics in international relations, specifically in war. Janina Dill investigates how legal and moral imperatives interact with strategic thinking and technological developments to explain conduct in war and the development of armed conflict. She also works on IR theory, specifically constructivism and the intersection of explanatory IR theories with normative political theory.

Her first book, entitled Legitimate Targets? International Law, Social Construction and US Bombing, proposes a constructivist theory of international law and highlights tensions between a legal and a moral definition of a legitimate target of attack. It appeared with Cambridge University Press as part of the series Cambridge Studies in International Relations in 2015. The book was Runner-Up for the Birks Prize for Outstanding Legal Scholarship of the Society of Legal Scholars in 2016, and it has received an Honourable Mention by the Theory Section of the International Studies Association.

Her second book (co-authored with Ziv Bohrer and Helen Duffy) proposes a moral division of labour between human rights and humanitarian law and examines under what empirical circumstances each body of law should prevail over the other. It is forthcoming with Cambridge University Press as part of the series Max Planck Trialogues on the Law of Peace and War.