Jacques Moreillon earned a PhD in Political Science at the Graduate Institute of International Studies in Geneva. His thesis on "The International Committee of the Red Cross and political detainees" led him to become an International Committee of the Red Cross (ICRC) delegate, first in India (1965), then in Vietnam (1966).

Dr Moreillon eventually moved on to become head of the delegation in Syria (1967), and Israel (1969-70) with missions to Nigeria/Biafra and to the Vatican in between. In 1971, he married Marie-Claude Langer (with whom he had two sons) and became Regional Delegate for South America, based in Caracas, and, in 1972, Delegate General for Africa. In his capacity as ICRC Delegate General for Africa  he visited  Nelson Mandela in his cell and without witness on Robben Island six times between 1973 and 1975 .They met again afterwards eight times between 1991 and 2004, before, during and after Mandela’s tenure as President of South Africa.

Member of the ICRC's Directorate from 1975 to 1988, he was successively Director of the Department of Doctrine and Law (as successor to Jean Pictet), then Director of General Affairs and finally Director General of the ICRC ad personam from 1984.

In November 1988, Dr Moreillon left his professional position at the ICRC to become Secretary General of the World Organisation of the Scout Movement (WOSM). Simultaneously, he became a member of the ICRC Council of the Assembly. 

During his 15-year mandate at the head of World Scouting, the active members of the Movement – the largest youth organisation in the world – increased from 16 to 28 million and from 120 to 155 countries, 105 of which Dr Moreillon conducted 415 missions. He retired from WOSM in April 2004.

In addition to his work at the ICRC, Dr Moreillon has served on various committees, such as Foundations Pro Victimis and Ousseimi, and in 2006, he was elected President of the Institute’s Alumni Association.
Amongst other recognitions, Dr Moreillon has been decorated as Chevalier de la Légion d’honneur by French Prime Minister Edouard Balladur. King Hassan II of Morocco granted him the Issam Alaoui Order, President Wade of Senegal, l’Ordre National du Lion, and the King of Sweden his Royal Order.

Mr Moreillon’s son, François, also an Institute alumnus, has also worked for the ICRC as delegate, deputy head of delegation and head of delegation on various continents for some twenty years.