Joanna Harrington has taught law for over twenty years.

​She began teaching law in 1997 as a graduate student at the University of Cambridge. Her first course was contract law, but she has since taught primarily public law subjects, including constitutional law, comparative civil liberties, international law, international criminal law, international dispute settlement, and international human rights law.

She regularly supervises J.D. students in directed research projects, including projects developed in collaboration with the non-profit sector. She also enjoys supervising lawyers in practice pursuing graduate studies, and has served as an external  supervisor for the University of Oxford's master’s program in international human rights law.

Before joining the University of Alberta in 2004, she held full-time academic appointments at the University of Nottingham and the University of Western Ontario (now Western University). She has also taught law as a visiting professor in Australia, China, Japan, Puerto Rico, and Suriname. In 2015, she was selected by the Shanghai Municipal Education Commission to teach international dispute settlement under the 'Recruitment Program of High-end Foreign Experts' run by the State Administration of Foreign Experts Affairs.

She has also contributed to several international capacity-building projects, starting out with a British Council project on the teaching of human rights within the Ukrainian police training institutes. She has since taught in Suriname as part of a collaborative project between the FHR Lim A Po Institute for Social Studies, the Surinamese government, and the United Nations Development Programme (UNDP). She developed and taught a course on international human rights reporting obligations for mid-career civil servants in 2008 and 2012.

She also contributes to training programs in international law for judges, diplomats, military officers and other government officials, serving as a guest instructor for the Canadian Foreign Service Institute and the Judge Advocate General’s continuing legal education program. She began this work as a contributor to the training program for members of the British judiciary following the enactment of the Human Rights Act 1998 and the incorporation of the European Convention on Human Rights into British law.

Recognizing that faculty also need training opportunities to support the continual development of their teaching, she co-organized the first Canadian "Teaching IHL Workshop" at the University of Alberta in 2012 in partnership with the Canadian Red Cross, the Canadian Forces Military Law Centre and the Washington Delegation of the International Committee of the Red Cross (ICRC). Bringing together law professors, military lawyers and humanitarian law practitioners, the two-day workshop focussed on how to teach international humanitarian law and the law of armed conflict in the Canadian law school setting, whether as a stand-alone course or as part of a course on constitutional law, international criminal law, international human rights law or national security law. A second workshop was held at Laval University in 2015, with a third workshop to be held at Carleton University in 2021-2022.