Susana Myrta Ruiz Cerutti (born 18 November 1940) is an Argentinian lawyer, diplomat and politician, who occupied the position of Minister of Foreign Affairs and Worship (canciller) during the presidency of Raúl Alfonsín, from 26 May to 8 July 1989. This made her the first woman in Argentina's history to reach the post of foreign minister. She previously served as deputy foreign minister from 1987 to 1989, when she became foreign minister, and later held other positions in that Ministry. During her diplomatic career she was also Argentinian ambassador to Switzerland, Liechtenstein and Canada.
Having graduated in law from the University of Buenos Aires (UBA), Ruiz Cerutti practiced her profession until her entry to the Diplomatic Academy of Argentina (Instituto del Servicio Exterior de la Nacion), from which she graduated in 1968 with a gold medal and Honors diploma.
Between 1972 and 1985 Ruiz Cerutti led or took part in several diplomatic missions that resolved the Beagle Channel dispute through papal mediation. She was Argentina's permanent representative at the United Nations and the Organization of American States (OAS), and represented Argentina in other organizations. She also headed the Argentinian delegation in negotiations with Chile over boundary issues stemming from the Laguna del Desierto incident.
After serving as legal advisor to Argentina's Foreign Ministry, she was appointed in 1987 as Secretary of State (vicanciller – "vicechancellor", Deputy Foreign Minister). In May 1989 she was appointed by President Raúl Alfonsín as Foreign Minister (canciller – "chancellor"), in place of Dante Caputo. She held that position for six weeks, until the inauguration as President of Carlos Menem, who appointed Domingo Cavallo as her successor on 9 July.
She then resumed the post of Secretary of State, until her appointment in 1991 as Argentine Ambassador to Switzerland: as such her credentials were also accepted in Liechtenstein. Later she was appointed Ambassador to Canada from 1998 to 1999. Between 1999 and 2000, she was Special Representative for Islas Malvinas (Falkland Islands) and Southern Atlantic Islands affairs, with the rank of ambassador. In November 2000, she was appointed Secretary for Foreign Policy, replacing Enrique Candioti, during the presidency of Fernando de la Rúa.
She was re-appointed Legal Adviser to the Foreign Ministry in 2001, a position she holds today. In that position she represented Argentina in the Uruguay River pulp mill dispute, between 2006 and 2010, when the issue was before the International Court of Justice in The Hague.
She was the candidate favored by the United Nations Security Council in November 2014 to take a place as judge at the International Court of Justice, but the General Assembly's choice of Patrick Lipton Robinson prevailed in the final vote.
For her work resolving the "Laguna del Desierto" boundary dispute with Chile, Ruiz Cerutti was awarded the Pro Ecclesia et Pontifice and the Order of St. Gregory the Great from Pope John Paul II.
She twice won the Konex Award, in 1998 and 2008, in the "Diplomacy" category.
In April 2012 she was appointed as Honorary Member of the Argentine National Academy of Geography, lecturing on "Geography in disputes between states", bringing to bear her expertise in international law.