| | Secretary-General | Country | Tenure | Exam-Oriented Facts |
| 1 | Trygve Lie | Norway | 1946–1952 | 1st Secretary-General |
| 2 | Dag Hammarskjöld | Sweden | 1953–1961 | Died in office; Nobel Peace Prize (1961, Posthumous) |
| 3 | U Thant | Myanmar (Burma) | 1961–1971 | 1st Asian Secretary-General |
| 4 | Kurt Waldheim | Austria | 1972–1981 | Later became President of Austria |
| 5 | Javier Pérez de Cuéllar | Peru | 1982–1991 | 1st Latin American Secretary-General |
| 6 | Boutros Boutros-Ghali | Egypt | 1992–1996 | 1st African Secretary-General |
| 7 | Kofi Annan | Ghana | 1997–2006 | Nobel Peace Prize (2001); 1st Secretary-General from UN staff |
| 8 | Ban Ki-moon | South Korea | 2007–2016 | Promoted Sustainable Development Goals (SDGs) |
| 9 | António Guterres | Portugal | 2017–Present (Incumbent, as of Aug 2026) | Former Prime Minister of Portugal and former UN High Commissioner for Refugees (UNHCR) |
