1918 state leaders - Events of 1919 - 1920 state leaders - State leaders by year

Africa

• Ethiopia - Zauditu, Emperor of Ethiopia (1916-1930)
• Liberia - Daniel E. Howard, President of Liberia (1912-1920)
• South Africa
  • Monarch - King George V, King of South Africa (1910-1936)
  • Governor-General - Viscount Buxton, Governor-General of South Africa (1914-1920)
  • Prime Minister -
    1. Louis Botha, Prime Minister of South Africa 1910-1919)
    2. Jan Smuts, Prime Minister of South Africa 1919-1924)
• Zanzibar - Sayyid Khalifa bin Harub Al-Busaid, Sultan of Zanzibar (1911-1960)

Asia

• Afghanistan
  • King -
    1. Habibullah Khan, King of Afghanistan (1901-1919)
    2. Nasrullah Khan , King of Afghanistan (1919-1919)
    3. Amanullah Khan, King of Afghanistan (1919-1926)
• Brunei - Muhammad Jamalul Alam II, Sultan of Brunei (1906–1924)
• China
  • President - Hsu Shih-Chang, President of the Republic of China (1918-1922)
  • Premier -
    1. Qian Nengxun , Premier of the Republic of China (1918-1919)
    2. Gong Xinzhan , Acting Premier of the Republic of China (1919)
    3. Jin Yunpeng , Premier of the Republic of China (1919-1920)
• Japan
  • Monarch - Taisho Emperor, Emperor of Japan (1912-1926)
  • Prime Minister - Hara Takashi, Prime Minister of Japan (1918-1921)
• Oman - Taimur Bin Faisal, Sultan of Oman (1913-1932)

Australia and Oceania

• Australia -
  • Monarch - George V, King of the United Kingdom (1910-1936)
  • Governor-General - Ronald Munro-Ferguson, Governor-General of Australia (1914-1920)
  • Prime Minister - Billy Hughes, Prime Minister of Australia (1915-1923)

Europe

• Albania - Turhan Pashë Permeti , Chairman of the Provisional Government (1918-1920)
• Denmark
  • Monarch - Christian X, King of Denmark (1912-1947)
  • Prime Minister - Carl Theodor Zahle, Prime Minister of Denmark (1913-1920)
• Finland -
  • Regent - Carl Gustaf Emil Mannerheim (December 1918-1919)
  • President - Kaarlo Juho Ståhlberg, President of Finland (1919-1925)
  • Prime Minister -
    1. Lauri Ingman, Prime Minister of Finland (1918-1919)
    2. Kaarlo Castrén , Prime Minister of Finland (1919)
    3. Juho Vennola , Prime Minister of Finland (1919-1920)
• France -
  • President - Raymond Poincaré, President of France (1913-1920)
  • Prime Minister - Georges Clemenceau, President of the Council (1917-1920)
• Germany -
  • Head of State -
    1. Central Council of the German Socialist Republic (1918-1919)
    2. Wilhelm Pfannkuch , President of the Constituent Assembly (1919)
    3. Eduard David , President of the Constituent Assembly (1919)
    4. Friedrich Ebert, Reichspräsident ("Reich President") (1919-1925)
  • Head of Government -
    1. Friedrich Ebert, Executive Chairman of the Council of People's Commissioners (1918-1919)
    2. Philipp Scheidemann, Prime Minister of Germany (1919)
    3. Gustav Bauer, Chancellor of Germany (1919-1920)
• Italy
  • Monarch - Vittorio Emanuele III, King of Italy (1900-1946)
  • Prime Minister -
    1. Vittorio Orlando, Prime Minister of Italy (1917-1919)
    2. Francesco Nitti, Prime Minister of Italy (1919-1920)
• United Kingdom -
  • Monarch - George V, King of the United Kingdom (1910-1936)
  • Prime Minister - David Lloyd George, Prime Minister of the United Kingdom (1916-1922)
• Romania - King Ferdinand (1914-1927)

North America and the Caribbean

• Canada
  • Monarch - King George V, King of Canada (1910-1936)
  • Governor-General - Duke of Devonshire, Governor-General of Canada (1916-1921)
  • Prime Minister - Sir Robert Borden, Prime Minister of Canada (1911-1920)
• Newfoundland
  • Monarch - King George V, King of Newfoundland {1910-1936}
  • Governor - Charles A. Harris , Governor of Newfoundland (1917-1922)
  • Prime Minister -
  1. William F. Lloyd, Prime Minister of Newfoundland (1918-1919)
  2. Michael Patrick Cashin, Prime Minister of Newfoundland (1919)
  3. Richard Squires, Prime Minister of Newfoundland (1919-1923)
• United States - Woodrow Wilson, President of the United States (1913-1921)

South America

• Brazil -
  1. Delfim Moreira, Acting President of Brazil (1918-1919)
  2. Epitâcio da Silva Pessoa, President of Brazil (1919-1922)
• Paraguay -
  1. Manuel Franco , President of Paraguay (1916-1919)
  2. José P. Montero , President of Paraguay (1919-1920)
• Peru -
  1. José Pardo y Barreda , President of Peru (1915-1919)
  2. Augusto B. Leguía y Salcedo, President of Peru (1919-1930)