Ban Ki-moon (born 13 June 1944) is the eighth and current Secretary-General of the United Nations, after succeeding Kofi Annan in 2007. Before becoming Secretary-General, Ban was a career diplomat in South Korea's Ministry of Foreign Affairs and in the United Nations. He entered diplomatic service the year he graduated from university, accepting his first post in New Delhi, India. In the foreign ministry, he established a reputation for modesty and competence.

Ban was the foreign minister of South Korea from January 2004 to November 2006. In February 2006, he began to campaign for the office of Secretary-General. Ban was initially considered to be a long shot for the office. As foreign minister of South Korea, however, he was able to travel to all of the countries that were members of the United Nations Security Council, a maneuver that turned him into the front runner.

On 11 October 2006, he was elected to be the eighth Secretary-General by the United Nations General Assembly and officially succeeded Annan on 1 January 2007. Ban has led several major reforms regarding peacekeeping and UN employment practices. Diplomatically, Ban has taken particularly strong views on Darfur, where he helped persuade Sudanese President Omar al-Bashir to allow peacekeeping troops to enter Sudan; and on global warming, pressing the issue repeatedly with former U.S. President George W. Bush. Ban has received strong criticism from OIOS, the UN internal audit unit, stating that the secretariat, under Ban's leadership, is "drifting into irrelevance".

In 2011, Ban ran unopposed for a second term as Secretary-General. On 21 June 2011, he was unanimously re-elected by the General Assembly and therefore will continue to serve until 31 December 2016.