Erik Franckx is a professor at the Vrije Universiteit Brussel, honorary professor at the Nelson Mandela University, as well as professeur émérite at the Université libre de Bruxelles. He holds moreover teaching assignments at the Sorbonne Université Abu Dhabi, United Arab Emirates; and the University of Akureyri, Iceland.  Besides numerous articles on the Law of the Sea, he has also updated, together with John Noyes and Kristen Juras, two standard works of Louis B. Sohn in this domain, namely The Law of the Sea in a Nutshell (West, 2^nd ed. 2010, 3^rd ed. In preparation) and Cases and Materials on the Law of the Sea (Brill, 2^nd ed. 2014).

He served between 2017 and 2022 as President of the Belgian Society for International Law and was appointed by Belgium as expert in marine scientific research for use in special arbitration under the 1982 United Nations Convention on the Law of the Sea (1982 Convention) since 2004, as expert in maritime boundary delimitation to the International Hydrographic Organization since 2005, and as arbitrator under the 1982 Convention starting in 2014.  Between 2006 and 2012 he was appointed by his country as member of the Permanent Court of Arbitration.

He has taught more than 20 short courses since 1992 in the following countries: China, Greece, Iceland, Japan, Philippines, Russian Federation, Sweden, Turkey, United Arab Emirates, United States, and Vietnam.

Between 2010 and 2023 he was an invited speaker at more than 150 international conferences around the world.

He served as a consultant to governments (foreign as well as the three levels of the Belgian state structure, i.e. the federal, regional and community level), international, supra national and non-governmental organizations. He was recently legal counsel on behalf of the Netherlands in the Arctic Sunrise Arbitration against the Russian Federation (2013 - 2017).