Katie is currently reading for a DPhil in Law, under the supervision of Professor Dapo Akande. Her research is in the field of Public International Law and investigates how the law on the use of force by states (jus ad bellum) can change, given that the law in this area comprises multiple norms, from different sources of law, some of which have identical content and some of which refer to or provide exceptions to each other.

Katie's research is supported by an Arts and Humanities Research Council (AHRC) studentship and a St Edmund Hall 'MCR 50th Anniversary' Postgraduate Scholarship. In 2019 Katie was a visiting research student at the Université Libre de Bruxelles, supported by a Postgraduate Research Grant from the Fondation Wiener-Anspach.

Originally from Northern Ireland, Katie completed her M.A. in Law with Law Studies in Europe and M.Phil. at the University of Oxford and also holds a Licence en Droit from the Université Paris II Panthéon-Assas. She completed her LL.M. in International Legal Studies at Georgetown Law in Washington, D.C., where she was a UK-US Fulbright Scholar.

Before returning to Oxford, Katie worked for the UK Law Commission, in the legal department of an international organisation, and most recently for a human rights NGO in Phnom Penh, Cambodia.


Recent additions

Journal Article (5)

Katie A. Johnston, 'The nature and context of rules and the identification of customary international law' (2021) European Journal of International Law (forthcoming)

Chapter (1)

Katie A. Johnston, '‘Force’ and ‘Déplorer’' in Valère Ndior (ed), Dictionnaire de l’actualité internationale (Pedone 2021)
DOI: 9782233009685

Internet Publication (3)

Research programmes

Research projects

Research Interests

Public International Law; Law of Armed Conflict; International Human Rights Law; Legal Theory

Options taught

Public International Law, International Law and Armed Conflict, Constitutional Law (Mods)

Research projects