Mr Ronald R. Nelson was born on 11 November 1941 in Sioux Falls, South Dakota, USA. He received his B.A. (History) from the University of South Dakota, and M.A. and Ph.D. (History) from Duke University in 1967. In addition, he attended senior military schools.

After military service in the Republic of Viet Nam, he taught history at Western Carolina University (1969-1973); served in the U.S. Army in Germany (1974-1977) and in Washington, D.C. (1977-1981). Thereafter, he served on the staff of the Senate Foreign Relations Committee, and as Deputy Representative to the Mutual and Balanced Force Reduction Talks in Vienna, Austria.

From 1985-1992, Mr Nelson, while Representative of the Secretary of Defense to the Conference on Disarmament in Geneva, participated in negotiating the Chemical Weapons Convention.

He was the Planning Officer for the Preparatory Commission of the OPCW (1993-1997), and Budget and Planning Officer in the OPCW (1997-2002).

In August 2005, he was appointed Director of Administration.