Gert Rosenthal Königsberger (born 11 September 1935) is a Guatemalan diplomat who served as Guatemala's Minister of Foreign Affairs from 25 July 2006 to 14 January 2008 under the government of Óscar Berger.

After secondary education in Guatemala, he studied in the United States and received a BA and an MA in economics from the University of California, Berkeley.

Between 1972 and 1973 he directed a project in Guatemala for the United Nations Conference on Trade and Development (UNCTAD), intended to promote the Central American Common Market.

Between 1974 and 1985 he was the Director of the Mexico-based subregional office of the United Nations Economic Commission for Latin America and the Caribbean (ECLAC).

Currently Rosenthal is the Chair of the Advisory Group of Experts on the Review of the United Nations Peacebuilding Architecture started in January 2015.