Prior to his work with the International Criminal Court, he was the Legal Advisor to the United Nations High Commissioner for Human Rights in Geneva.

After obtaining his master of laws degree from McGill in 1991, he worked as a barrister in Canada, having been called to the Bar in Ontario and in British Columbia in 1993.

Working for the Special Court for Sierra Leone as senior prosecution appeals counsel in 2007/08 and returning to the ICTR from 2008 to 2010 as Head of Chambers, he became the Legal Advisor to the United Nations High Commissioner for Human Rights Navi Pillay in 2010,[1] and held a cross-appointment as the principal prosecution appeals counsel at the Special Court for Sierra Leone, in the case of Charles Taylor, the former President of Liberia.

However, Eboe-Osuji remained the Presiding Judge in Trial Chamber V(a) which continued to hear the case against Ruto and former Kass FM broadcaster Joshua Sang until his term at the court ended in 2021.

[6] Shortly after, Eboe-Osuji told off the government of Kenya for turning to the principle of sovereignty "at every convenient opportunity, with the evident aim of frightening judges".