1900

• 1900 in film
• 1900 in literature
• 1900 in science
• 1900 in music
• 1900 in sports

• January 2 - John Hay announces the Open Door Policy to promote trade with China.
• January 2 - Chicago Canal opens.
• January 5 - Irish leader John Edward Redmond calls for a revolt against British rule.
• January 6 - It is reported that millions are starving in India.
• January 6 - Boers attack Ladysmith - over 1000 people killed
• January 8 - United States President William McKinley places Alaska under military rule.
• January 16 - The United States Senate accepts the Anglo-German treaty of 1899 in which the United Kingdom renounced its claims to the Samoan islands
• January 27 - Boxer rebellion: Foreign diplomats in Peking China demand that the Boxer rebels be disciplined.
• January 29 - The American League is organized in Philadelphia, Pennsylvania with 8 founding teams.
• January 30 - United Kingdom forces fighting Boers in South Africa ask for reinforcements.
• February 3 - Gubernatorial candidate William Goebels is assassinated in Frankfort, Kentucky. Former-Secretary of State Caleb Powers was later found guilty in a conspiracy to kill Goebels.
• February 7 - The British Labour Party is formed
• February 8 - British troops are defeated by Boers at Ladysmith, South Africa
• February 9 - Richard Wigginton Thompson, congressman
• February 14 - Russia responds to international pressure to free Finland by tightening imperial control over the country.
• February 14 - Boer War: In South Africa, 20,000 British troops invade the Orange Free State
• February 22 - Hawaii officially becomes a territory of the United States.
• February 23 - Boer War: Battle of Hart's Hill - In South Africa the Boers and British troops battle.
• February 27 - Boer War: In South Africa, British military leaders receive an unconditional notice of surrender from Boer General Piet Cronje.
• February 27 - Ramsay MacDonald appointed secretary of newly formed British Labour Party
• March 6 - A coal mine explosion in West Virginia traps 50 coal miners.
• March 11 - Boer War: Boer leader Paul Kruger's peace overtures are rejected by Prime Minister of the United Kingdom Lord Salisbury.
• March 13 - Boer Wars: British forces occupy Bloemfontein, Orange Free State.
• March 14 - The Gold Standard Act is ratified placing United States currency on the gold standard.
• March 16 - Sir Arthur Evans discovers the ruins of Knossos on Crete
• March 24 - New York City Mayor Van Wyck breaks ground for a new underground "Rapid Transit Railroad" that would link Manhattan and Brooklyn.
• May 17 - Boer War: British troops relieve Mafeking
• May 18 - The United Kingdom proclaims a protectorate over Tonga.
• May 23 - Sergeant William Harvey Carney becomes the first African American to be awarded the Congressional Medal of Honor (awarded for heroism in the Battle of Fort Wagner during the American Civil War).
• May 24 - British annex Orange Free State as Orange River Colony
• May 31 - British take Johannesburg
• June 5 - British take Pretoria
• July 2 - First zeppelin flight on Lake Constance near Friedrichshafen, Germany
• July 5 - Commonwealth of Australia Constitution Act passes British Parliament
• July 9 - Queen Victoria gives royal assent to Commonwealth of Australia Constitution Act
• July 29 - In Italy, King Umberto I of Italy is assassinated by Italian-born anarchist Gaetano Bresci.
• July 30 - The Duke of Albany becomes Duke of Saxe-Coburg and Gotha as Karl Eduard following the death of his uncle, Duke Alfred
• July 13 - Boxer Rebellion: In China, Tientsin is retaken by European Allies from the rebelling Boxers.
• August 27 - British defeat Boer commandos at Bergendal
• September 8 - 1900 Galveston Hurricane: A large hurricane hits Galveston, Texas killing about 6,000 people.
• September 17 - Philippine-American War: Filipinos under Juan Cailles defeat Americans under Colonel Benjamin F. Cheatham at Mabitac.
• November 6 - U.S. presidential election, 1900: Republican incumbent William McKinley is reelected by defeating Democrat challenger William Jennings Bryan.

• January 27 - Admiral Hyman Rickover, American admiral, proponent of the "nuclear Navy" (d. 1986)
• January 28 - Heinrich Kesten, author (d. 1996)
• February 4 - Jacques Prevert, lyricist and author (d. 1977)
• February 5 - Adlai Stevenson, politician (d. 1965)
• February 11 - Thomas Hitchcock Jr, polo player (d. 1944)
• February 11 - Hans-Georg Gadamer, German philosopher (d. 2002)
• February 22 - Luis Buñuel, film director (d. 1983)
• February 28 - Wolfram Hirth, pilot and designer of aircrafts (d. 1959)
• March 9 - Howard Aiken, computing pioneer
• March 13 - George Seferis, Nobel prize-winning poet (d. 1971)
• March 19 - Frédéric Joliot, scientist
• March 23 - Erich Fromm, psychologist, philosopher (d. 1980)
• March 29 - John McEwen, eighteenth Prime Minister of Australia (d. 1980)
• March 31 - Richard Alexander Walter Windsor, Duke of Gloucester
• April 5 - Spencer Tracy, actor (d. 1967)
• April 25 - Wolfgang Ernst Pauli, physicist
• April 26 - Charles Richter, geophysicist, inventor (d. 1985)
• April 30 - Cecily Lefort, SOE agent, WW II heroine, executed by the Nazis (d. 1945)
• May 1 - Ignazio Silone, Italian author; in Abruzzo region of Italy
• May 12 - Helene Weigel, actress (d. 1971)
• May 17 - Ruhollah Khomeini (d. 1989)
• May 28 - Tommy Ladnier, jazz musician (d. 1939)
• June 15 - Paul Mares, jazz musician (d. 1949)
• June 29 - Antoine de Saint-Exupery, French pilot and writer
• July 13 - George Lewis, jazz musician (d. 1969)
• August 3 - Ernie Pyle, American journalist
• August 4 - Elizabeth Bowes-Lyon, The Queen Mother of the United Kingdom (d. 2002)
• August 6 - Cecil H. Green, founder of Texas Instruments (d. 2003)
• August 22 - Sergei Ozhegov, Russian lexicographer (d. 1964)
• August 25 - Sir Hans Adolf Krebs, German medical doctor and biochemist
• August 26 - Hellmuth Walter, engineer and inventor (d. 1980)
• September 6 - W.A.C. Bennett, British Columbia politician (d. 1979)
• November 8 - Charlie Paddock, American athlete

• April 30 - John Luther Jones, better known as Casey Jones, train wreck
• May 18 - Jean Gaspard Felix Ravaisson-Mollien, French philosopher
• June 5 - Stephen Crane, American author; in Badenweiler, Baden, Germany
• July 19 - King Umberto I of Italy; (assassinated) in Monza, near Milan, Italy
• July 30 - Duke Alfred of Saxe-Coburg-Gotha, second son of Queen Victoria of the United Kingdom
• August 25 - Friedrich Nietzsche, philosopher, writer; in Germany
• September 23 - William Marsh Rice philanthropist, founder of Rice University; (murdered) in New York City
• November 30 - Oscar Wilde, British author, playwright; in Paris, France

• China - Guāngxù Emperor of China, Qing Dynasty (1875-1908)
• Denmark - Christian IX, King of Denmark (1863-1906)
• France - Émile Loubet, President of France (1899-1906)
• Germany - Wilhelm II, German Kaiser (1888-1918)
• Holy See - Pope Leo XIII, Bishop of Rome (1878-1903)
• Japan - Mutsuhito, Meiji Emperor (1867-1912)
• Norway - Oscar II, King of Sweden and Norway (1872-1905)
• Ottoman Empire - Abdul Hamid II, Sultan of the Ottoman Empire (1876-1909)
• Russia - Nicholas II, Tsar of Russia (1894-1917)
• Spain - Alfonso XIII of Spain, King of Spain (1886-1931)
• United States - William McKinley, President of the United States (1897-1901)