List of state leaders in 1865 - Events of 1866 - List of state leaders in 1867 - State leaders by year

Africa

• Ashanti Confederacy - Kwaku Dua I Panyin, Asantehene (1834-1867)
• Buganda - Mutesa I, King of Buganda (1856-1884)
• Bunyoro - Kyebambe IV, Omukama of Bunyoro (1852-1869)
• Burundi - Mwezi IV Gisabo, King of Burundi (1852-1908)
• Dahomey - Glele, King of Dahomey (1856-1889)
• Ethiopia - Tewodros II, Emperor of Ethiopia (1855-1868)
• Liberia - Daniel Bashiel Warner, President of Liberia (1864-1868)
• Rwanda - Kigeli IV, King of Rwanda (1853-1895)
• Sokoto Caliphate
  • Caliph -
    1. Ahmad bin Atiku, Sokoto Caliph (1859-1866)
    2. Ali bin Bello II, Sokoto Caliph (1866-1867)
  • Grand Vizier - Ibrahim Khalilu, Sokoto Grand Vizier (1859-c.1874)
• Zanzibar - Sayyid Majid bin Said Al-Busaid, Sultan of Zanzibar (1856-1870)
• Zulu - Mpande kaSenzangakhona, King of the Zulu (1840-1872)

Asia

• Afghanistan
  • Emir -
    1. Shir Ali Khan, Emir of Afghanistan (1863-1866)
    2. Mohammed Afzal Khan, Emir of Afghanistan (1866-1868)
• China (Qing Dynasty) - Tóngzhì, Emperor of China (1861-1875)
• Japan
  • Monarch - Kōmei, Emperor of Japan (1846-1867)
  • Shogun (Tokugawa) - Tokugawa Iemochi, Shogun of Japan (1858-1866)
  • Ryūkyū Kingdom - Shō Tai, King of Ryūkyū (1848-11 March 1879)
• Korea (Joseon Dynasty) - Gojong, King of Joseon (1864-1907, Emperor after 1897)
• Oman -
  1. Thuwaini bin Said, Sultan of Oman (1856-1866)
  2. Salim bin Thuwaini, Sultan of Oman (1866-1868)

Europe

• Belgium
  • Monarch - Léopold II, King of the Belgians (1865-1909)
  • Cabinet Chief - Charles Rogier, Cabinet Chief of Belgium (1847-1852, 1857-1868)
• Denmark
  • Monarch - Christian IX, King of Denmark (1863-1906)
  • Prime Minister - Christian Emil, Prime Minister of Denmark (1865-1870)
• France - Napoleon III, Emperor of the French (1852-1870)
• German Confederation - dissolved in 1866 as a result of the Austro-Prussian War
  • Franz Joseph of Austria, President of the German Confederation (1850-1866),
  • Austria - Franz Joseph I, Emperor of Austria (1848-1916)
  • Luxembourg
    • Monarch - William III, King of the Netherlands (1849-1890)
    • Prime Minister - Victor, Baron de Tornaco, Prime Minister of Luxembourg (1860-1867)
  • Prussia -
    • Monarch - Wilhelm I, King of Prussia (1861-1888)
    • Prime Minister - Otto von Bismarck, Minister-President of Prussia (1862-1873)
  • Bavaria - Ludwig II, King of Bavaria (1864-1886)
  • Saxony - Johann, King of Saxony (1854-1873)
  • Hanover -
    • George, King of Hanover (1851-1866)
    • Defeated and annexed by Prussia in 1866
  • Württemberg - Karl, King of Württemberg (1864-1891)
• Papal States - Pope Pius IX (1846-1878)
• Italy -
  • Monarch - Vittorio Emanuele II, King of Italy (1861-1878)
  • Prime Minister -
    1. Marchese la Marmora, Prime Minister of Italy (1864 - 1866)
    2. Bettino Ricasoli, Prime Minister of Italy (1866-1867)
• Netherlands
  • Monarch - William III, King of the Netherlands (1849-1890)
  • Prime Minister -
    1. Jan Rudolf Thorbecke, Chairman of the Dutch council of ministers (1849-1853, 1862-1866, 1871-1872)
    2. Isaäc Dignus Fransen van de Putte, Chairman of the Dutch council of ministers (1866)
    3. Julius van Zuylen van Nijevelt, Chairman of the Dutch council of ministers (1866-1868)
• Norway - United Kingdoms of Sweden and Norway - Carl IV, King of Norway (1859-1872)
• Ottoman Empire - Abd-ul-Aziz, Sultan of the Ottoman Empire (1861-1876)
• Portugal - Luis, King of Portugal (1861-1889)
• Romania
  • Prince -
    1. Alexander John Cuza, Prince of Romania (1859-1866)
    2. Carol I, Prince of Romania (1866-1881)
• Russia - Alexander II, Tsar of Russia (1855-1881)
• Spain - Isabella II, Queen of Spain (1833-1868)
• Sweden - United Kingdoms of Sweden and Norway - Charles XV, King of Sweden (1859-1872)
• United Kingdom
  • Monarch - Victoria, Queen of the United Kingdom (1837-1901)
  • Prime Minister -
    1. John Russell, 1st Earl Russell, Prime Minister of the United Kingdom (1865-1866)
    2. Edward Smith-Stanley, 14th Earl of Derby, Prime Minister of the United Kingdom (1852, 1858, 1866-1868)

Middle East and North Africa

• Abu Dhabi - Zaid ibn Khalifa, Shaikh of Abu Dhabi (1855-1909)
• Egypt - Ismail, Governor of Egypt (1863-1867)
• Morocco - Mohammed IV, Sultan of Morocco (1859-1873)
• Ottoman Empire
  • Monarch - Abd-ul-Aziz, Sultan of the Ottoman Empire (1861-1876)
  • Grand Vizier -
    1. Keçecizade Mehmed Fuad Pasha, Ottoman Grand Vizier (1863-1866)
    2. Mütercim Mehmed Rüstü Pasha, Ottoman Grand Vizier (1866-1867)

North America

• Province of Canada
  • Governor: The Viscount Monck of Ballytrammon, Governor of the Province of Canada (1861–1867)
  • Joint Premiers: Sir John A. Macdonald and Sir Narcisse-Fortunat Belleau, Joint Premiers of the Province of Canada (1865–1867)
• Costa Rica -
  1. Jesús Jiménez Zamora, President of Costa Rica (1863–1866)
  2. José María Castro Madriz, President of Costa Rica (1866–1868)
• Mexico: Maximilian of Habsburg, Emperor of Mexico (1864–1867)
• United States: Andrew Johnson, President of the United States (1865–1869)

Oceania

• Hawaii - Kamehameha V, King of Hawaiʻi (1863-1872)
• Samoa - Malietoa Talavou Tonumaipe’a, Malietoa (1860-1880)
• Tonga - Tāufaʻāhau, Tu'i Kanokupolu (1845-1893)

South America

• Brazil - Pedro II, Emperor of Brazil (1831-1889)
• Uruguay - Venancio Flores, President of Uruguay (1865-1868)

List of state leaders in 1865 - Events of 1866 - List of state leaders in 1867 - State leaders by year