Rafael Mariano Grossi is an Argentine diplomat. He has been serving as Director General of the International Atomic Energy Agency (IAEA) since December 3, 2019. He was formerly the Argentine Ambassador to Austria, concurrent with Slovenia, Slovakia and International Organisations based in Vienna (2013–2019).
Grossi began working in nuclear policy during a collaboration between the Argentine foreign service and INVAP. Between 1997 and 2000 he was the President of the United Nations Group of Government Experts on the International Weapons Registry, and later became adviser to the Assistant Secretary-General of the United Nations on disarmament.
From 2002 to 2007 he was Chief of Staff of the International Atomic Energy Agency and the Organisation for the Prohibition of Chemical Weapons. While working for the United Nations, Grossi visited North Korea's nuclear facilities and participated in several meetings with representatives of Iran to reach an agreement to freeze its nuclear program.
During his work for the Argentine foreign service, he was the General Director of Political Coordination of the Ministry of Foreign Affairs and Worship, Ambassador to Belgium and the Argentine Representative to the United Nations Office at Geneva. Between 2010 and 2013 he served as Deputy Director General of the International Atomic Energy Agency, and that last year, President Cristina Fernández de Kirchner assigned him as Ambassador to Austria and International Organisations based in Vienna, concurrent also in Slovakia and Slovenia.
In September 2015, the Argentine government announced the nomination of Grossi as a candidate for Director General of the IAEA, with support from other countries in Latin America and the Caribbean. In 2016, however, the government of Mauricio Macri withdrew its support to promote Susana Malcorra's candidacy as UN Secretary General. In 2016, he was the President of the Nuclear Suppliers Group.
In 2017, President Macri announced that he would nominate Grossi for the presidency of the Review Conference of the Treaty on the Non-Proliferation of Nuclear Weapons to be held in 2020.