A German national, served until 31 December 2014 as Assistant Director-General for Strategic Planning of UNESCO, having also been designated in 2010 as Acting Deputy Director-General of the Organization. His responsibilities included global strategic planning and policy development, establishment and management of biennial programme and budget documents, results-based budgeting, risk management, extrabudgetary resource mobilization and partnerships, least developed countries, institutes and centres under the auspices of UNESCO (category 2) and UN systemwide reform issues, including the post-2015 development agenda. He also chaired the Intersectoral Platform for a culture of peace and non-violence and the UNESCO/Nigeria Task Force. As a member of the senior management team, he represented the Director-General in meetings of the UN General Assembly, the Economic and Social Council and various UN system coordination bodies. – Since January 2014, he was also directing the Secretariat for the Scientific Advisory Board of the UN Secretary-General, chaired by the UNESCO Director-General. He also was responsible for the organization of the annual International Jazz Day by UNESCO.

Prior to joining UNESCO in 2000, Mr d'Orville was (1996-2000) Director of the Information Technologies for Development Programme in the Bureau for Development Policy of UNDP and helped present ICTs as a global policy challenge to the G-8 summit in 2000. In 1975 he had been selected through a competitive national examination for appointment to the United Nations Secretariat, where he has held various functions, among others Secretary of the UN Committee on Conferences, later on in UNDP, as Senior Officer in the Office of the UNDP Administrator with responsibility for UNDP's Governing Council, technical cooperation among developing countries (South-South cooperation) and the UNDP Development Study Programme. Between 1987 and 1995, he was Executive Coordinator of the InterAction Council of former Heads of State and Government, chaired by former German Chancellor Helmut Schmidt and comprising more than 30 former world leaders – including Olusegun Obasanjo, Takeo Fukuda, Pierre Elliott Trudeau, Lord Callaghan, Miguel de la Madrid - which held annual summit meetings and engaged in lobbying for joint policy recommendations covering a broad range of political, economic and environmental issues.