|Covid-19|January 7 – The distress signal CQD is established, only to be replaced 2 years later by SOS.
January 12 – Henry Ford sets a new automobile land speed record of 91.37 mph (147.05 km/h).
January 16 – The first large-scale bodybuilding competition in America takes place at Madison Square Garden in New York City.
January 18 – The Herero Rebellion in German South-West Africa begins.
January 23 – The Ålesund Fire destroys most buildings in the town of Ålesund, Norway, leaving about 10,000 people without shelter.
January 25 – Halford Mackinder presents a paper on "The Geographical Pivot of History" to the Royal Geographical Society of London in which he formulates the Heartland Theory, originating the study of geopolitics.
February 7 – The Great Baltimore Fire in Baltimore, Maryland, destroys over 1,500 buildings in 30 hours.
February 8–9 – Battle of Port Arthur: A surprise Japanese naval attack on Port Arthur (Lüshun) in Manchuria starts the Russo-Japanese War.
February 10 – Roger Casement publishes his account of Belgian atrocities in the Congo.
February 17 – Puccini's opera Madama Butterfly, with a background theme of Japan–United States relations, debuts at La Scala in Milan to no great acclaim. On May 28 a revised version opens in Brescia to huge success.
February 23 – For $10 million, the United States gains control of the Panama Canal Zone.
February 28 – Sport Lisboa e Benfica is founded in Portugal.
March 3 – Kaiser Wilhelm II of Germany becomes the first person to make a political recording of a document, using Thomas Edison's cylinder.
March 4 – Russo-Japanese War: Russian troops in Korea retreat toward Manchuria, followed by 100,000 Japanese troops.
March 26 – 80,000 demonstrators gather in Hyde Park, London, to protest against the importation of Chinese labourers to South Africa by the British government.
March 31 – British expedition to Tibet – Battle of Guru: British troops under Colonel Francis Younghusband defeat ill-equipped Tibetan troops.
April 6 – Joseph F. Smith announces the Second Manifesto in General Conference of The Church of Jesus Christ of Latter-day Saints, ending in fact the practice of plural marriage which had continued to be practiced by many of its leaders in violation of the 1890 Manifesto officially banning the practice.
The Entente Cordiale is signed between the UK and France.
Longacre Square in Midtown Manhattan is renamed Times Square after The New York Times.
Aleister Crowley begins writing Liber Al vel Legis, better known as The Book of the Law, a text central to Thelema. He completes this task on April 10.
April 19 – The Great Toronto Fire destroys much of that city's downtown, but there are no fatalities.
April 27 – The Australian Labor Party becomes the first such party to gain national government, under Chris Watson.
April 30 – The Louisiana Purchase Exposition World's Fair opens in St. Louis, Missouri (closes December 1).
United States Army engineers begin work on the Panama Canal.
German football club FC Schalke 04 is established.
Pitching against the Philadelphia Athletics, Cy Young of the Boston Americans throws the first perfect game in the modern era of baseball.
British expedition to Tibet: Hundreds of Tibetans attack the British camp at Changlo and, for a while, hold the advantage before being defeated by superior weapons and losing at least 200 men.
May 9 – Great Western Railway of England 3700 Class 3440 City of Truro becomes the first railway locomotive to exceed 100 mph (probably).
May 15– The Russian minelayer Amur lays a minefield about 15 miles (24 km) off Port Arthur and sinks Japan's battleships Hatsuse, 15,000 tons, with 496 crew and Yashima.
May 21 – The International Federation of Association Football, FIFA, is established.
May 30 – Alpha Gamma Delta, which becomes an international women's fraternity, is founded by 11 women at Syracuse University.
June 10 – Irish author James Joyce meets his future wife Nora Barnacle.
June 15 – A fire aboard the steamboat General Slocum in New York City's East River kills 1,021.
Eugen Schauman assassinates Nikolai Bobrikov, Governor-General of Finland.
James Joyce walks to Ringsend with Nora Barnacle; he later uses this date (Bloomsday) as the setting for his novel Ulysses.
June 28 – The Danish ocean liner SS Norge runs aground and sinks close to Rockall, killing 635, including 225 Norwegian emigrants.
June 28 – The original icon of Our Lady of Kazan was stolen and subsequently destroyed in Russia.
June 29 – The 1904 Moscow tornado occurs.
July 1 – The third Modern Olympic Games opens in St. Louis, Missouri, United States as part of the World's Fair is 1st Summer Olympic Games of the 20th Century.
August 3 – British expedition to Tibet: The British expedition under Colonel Francis Younghusband takes Lhasa in Tibet.
August 11 – Battle of Waterberg: Lothar von Trotha defeats the Herero in German South-West Africa and drives them into the Omaheke desert, start of the Herero and Namaqua Genocide.
August 14 – Ismael Montes becomes President of Bolivia.
August 17 – Russo-Japanese War: A Japanese infantry charge fails to take Port Arthur.
August 18 – Chris Watson resigns as Prime Minister of Australia and is succeeded by George Reid.
August 22 – China's Deng Xiaoping (邓小平）is born in Sichuan Province.
September 2 – The rigged dugout canoe Tilikum sails into the River Thames in England after a 3-year voyage from Victoria, British Columbia westabout.
September 7 – British expedition to Tibet: The Dalai Lama signs the Anglo-Tibetan Treaty with Colonel Francis Younghusband.
September 25 – The Church of Jesus Christ of Latter-day Saints President Joseph F. Smith issues a Second Manifesto against polygamy.
September 26 – New Zealand dolphin Pelorus Jack is individually protected by Order in Council under the Sea Fisheries Act.
October 1 – Phi Delta Epsilon, the international medical fraternity, is founded by Aaron Brown and eight of his friends at Cornell University Medical College.
October 5 – Alpha Kappa Psi, the co-ed Professional Business Fraternity, is founded on the campus of New York University.
October 9 – German journalist Anna Rüling, in a speech to the Scientific-Humanitarian Committee in Berlin, makes the first known public statement of the socio-legal problems faced by lesbians.
October 15 – Theta Tau, the Professional Engineering Fraternity, is founded at the University of Minnesota in Minneapolis.
October 19 – Polytechnic University of the Philippines is founded as Manila Business School through the superintendence of the American C.A. O'Reilley.
October 21 – Russo-Japanese War – Dogger Bank incident: The Russian Baltic Fleet fires on British trawlers it mistakes for Japanese torpedo boats in the North Sea.
October 27 – The first underground line of the New York City Subway opens.
October 28 – Panama and Uruguay establishes diplomatic links.
November 8 – U.S. presidential election, 1904: Republican incumbent Theodore Roosevelt defeats Democrat Alton B. Parker.
November 16 – The settlement at Grytviken on the British South Atlantic island territory of South Georgia is established by Norwegian sea captain Carl Anton Larsen as a whaling station for his Compañía Argentina de Pesca.
November 24 – The first successful caterpillar track is made (it later revolutionizes construction vehicles and land warfare).
December 2 – The St. Petersburg Soviet urges a run on the banks: the attempt fails and the executive committee is arrested.
December 3 – Charles Dillon Perrine discovers Jupiter's largest irregular satellite, Himalia.
December 4 – The K.U. or Konservativ Ungdom (Young Conservatives) is founded by Carl F. Herman von Rosen in Denmark.
December 6 – Theodore Roosevelt announced his "Corollary" to the Monroe Doctrine, stating that the United States would intervene in the Western Hemisphere should Latin American governments prove incapable or unstable.
December 10 – The Pi Kappa Phi fraternity is founded at the College of Charleston in Charleston, SC.
December 27 – The stage play Peter Pan, or The Boy Who Wouldn't Grow Up premieres in London.
December 30 – The East Boston Tunnel opens.
December 31 – In New York City, the first New Year's Eve celebration is held in Times Square.
The Loftus Road and Griffin Park football stadiums open in London.
Stuyvesant High School is founded in New York City.
St. Bernard's School is founded in New York City.
The Daytona Educational and Industrial Training School for Negro Girls, now Bethune-Cookman University, is founded.
The subject of alcohol and heart attacks is first investigated.
January 1 – Fazal Ilahi Chaudhry, Pakistani politician (d. 1982)
January 5 – Jeane Dixon, American astrologer (d. 1997)
January 10 – Ray Bolger, American actor, singer, and dancer, better known for his role in The Wizard of Oz(d. 1987)
January 13 – Richard Addinsell, British composer (d. 1977)
Cecil Beaton, English photographer (d. 1980)
Ernst Wellmann, highly decorated German Army officer (d. 1970)
January 18 – Cary Grant, English actor (d. 1986)
January 19 – Leo Soileau, Cajun musician (d. 1980)
January 21 – Edris Rice-Wray Carson (d. 1990)
George Balanchine, Russian-born choreographer (d. 1983)
Arkady Gaidar, Russian children's writer (d. 1941)
Ancel Keys, American scientist (d. 2004)
Seán MacBride, Irish statesman, recipient of the Nobel Peace Prize (d. 1988)
January 27 – J. J. Gibson, American psychologist (d. 1979)
January 28 – Canuplin, Filipino magician and bodabil entertainer (d. 1979)
January 29 – Arnold Gehlen, German philosopher (d. 1976)
Ángel Borlenghi, Argentine labor leader and politician (d. 1962)
S. J. Perelman, American humorist and author (d. 1979)
Luigi Dallapiccola, Italian composer (d. 1975)
Pretty Boy Floyd, American gangster (d. 1934)
February 4 – MacKinlay Kantor, American writer and historian (d. 1977)
John Farrow, Australian film director (d. 1963)
Zacharias Roy, The 1st Teamspeak User
February 11 – Sir Keith Holyoake, 26th Prime Minister of New Zealand (d. 1983)
George F. Kennan, American diplomat (d. 2005)
Philip Rabinowitz (runner), South African record breaking sprinter (d. 2008)
James Baskett, African-American actor (Uncle Remus in Disney's Song of the South) (d. 1948)
February 20 – Alexei Kosygin, Premier of the Soviet Union (d. 1980)
February 22 – Ernst Jakob Henne, German motorcycle racer and racecar driver (d. 2005)
February 29 – Jimmy Dorsey, American bandleader (d. 1957)
Glenn Miller, American bandleader (d. 1944)
Paul Hartman, American actor and dancer (d. 1973)
March 2 – Dr. Seuss, American children's author (The Cat in the Hat) (d. 1991)
George Gamow, Ukrainian-born physicist (d. 1968)
Joseph Schmidt, Austrian-Hungarian tenor and actor (d. 1942)
Chief Tahachee, American-born stage and film actor (d. 1978)
March 5 – Mow Pang Tzu, Republic of China air force general (d. 1987)
March 6 – Hugh Williams, English actor and dramatist (d. 1969)
March 7 – Reinhard Heydrich, German Nazi official (d. 1942)
March 14 – Doris Eaton Travis, American actress (d. 2010)
March 15 – J. Pat O'Malley, English actor (d. 1985)
March 20 – Frank Mills (politician), American politician in Ohio legislature (1969)
B. F. Skinner, American behavioral psychologist (d. 1990)
March 22 – Itche Goldberg, Yiddish author (d. 2006)
Gustave Biéler, Swiss-born hero of World War II (executed) (d. 1944)
Joseph Campbell, American author on mythology (d. 1987)
Xenophon Zolotas, Prime Minister of Greece (d. 2004)
April 1 – Nikolai Berzarin, Russian Red Army General (d. 1945)
April 3 – Sally Rand, American dancer and actress (d. 1979)
April 6 – Kurt Georg Kiesinger, former Chancellor of West Germany (d. 1988)
April 8 – John Hicks, English economist, Nobel Prize laureate (d. 1989)
April 9 – Sharkey Bonano, American jazz musician (d. 1972)
April 13 – Elwood "Pete" Quesada, American air force general (d. 1993)
April 14 – John Gielgud, English actor (d. 2000)
April 15 – Arshile Gorky, Armenian-born painter (d. 1948)
April 16 – Fifi D'Orsay, Canadian actress (d. 1983)
April 22 – J. Robert Oppenheimer, American physicist (d. 1967)
April 24 – Willem de Kooning, Dutch artist (d. 1997)
April 26 – Jimmy McGrory, Scottish footballer (d. 1982)
Cecil Day-Lewis, English poet (d. 1972)
Syd Nathan, American record producer and music industry executive, founder of King Records (d. 1968)
April 29 – Pedro Vargas, Mexican singer and actor (d. 1989)
Joaquín García Morato, Spanish fighter ace (d. 1939)
Umm Kulthum, Egyptian singer and actress (d. 1975)
Moshé Feldenkrais, Ukrainian-born engineer (d. 1984)
Harry Martinson, Swedish writer, Nobel Prize laureate (d. 1978)
May 8 – John Snagge, British radio personality (d. 1996)
May 10 – James Roy Andersen, American general (d. 1945)
May 11 – Salvador Dalí, Spanish artist (d. 1989)
Marie-Anne Desmarest, French novelist (d. 1973)
Jean Gabin, French actor (d. 1976)
May 20 – Margery Allingham, British detective fiction writer (d. 1966)
Fats Waller, American pianist and comedian (d. 1943)
Robert Montgomery, American actor and director (d. 1981)
May 22 – Anne de Vries, Dutch writer (d. 1964)
May 25 – Charles L. Melson, United States Navy admiral (d. 1981)
May 26 – George Formby, English singer and comedian (d. 1961)
May 27 – Chūhei Nambu, Japanese athlete (d. 1997)
May 30 – Doris Packer, American actress (d. 1979)
František Plánička, Czech footballer (d. 1996)
Johnny Weissmuller, American swimmer and actor (Tarzan) (d. 1984)
June 3 – Jan Peerce, American tenor (d. 1984)
Heinrich von Brentano, German politician (d. 1964)
June 7 – Werner Gruner, German weapons designer (d. 1995)
Francisco López Merino, Argentine poet (d. 1928)
June 8 – Angus McBean, Welsh photographer (d. 1990)
June 18 – Keye Luke, Chinese-born American actor (d. 1991)
June 22 – William O. Gallery, American admiral (d. 1981)
June 24 – Phil Harris, American actor (d. 1995)
June 26 – Peter Lorre, Hungarian-born film actor (d. 1964)
June 27 – Huguette Masson, French supercentenarian
July 2 – René Lacoste, French tennis player and businessman (d. 1996)
July 5 – Ernst Mayr, German-born biologist and author (d. 2005)
July 6 – Erik Wickberg, General of The Salvation Army (d. 1996)
July 8 – Henri Cartan, French mathematician (d. 2008)
July 9 – Hideo Oguni, Japanese writer (d. 1996)
July 12 – Pablo Neruda, Chilean poet, Nobel Prize laureate (d. 1973)
July 15 – Rudolf Arnheim, German-born author (d. 2007)
July 24 – Nikolay Gerasimovich Kuznetsov, Soviet admiral (d. 1974)
July 26 – Edwin Albert Link, American pioneer in aviation, underwater archaeology, submersibles, inventor of aeronautical, navigation, and oceanographic equipment (d. 1981)
July 28 – Pavel Cherenkov, Soviet physicist, Nobel Prize laureate (d. 1990)
July 29 – J. R. D. Tata, Indian businessman (d. 1993)
Dolores del Río, Mexican actress (d. 1983)
Witold Gombrowicz, Polish novelist and dramatist (d. 1969)
Helen Kane, American singer, dancer, comedian, and actress (d. 1966)
August 7 – Ralph Bunche, American diplomat, recipient of the Nobel Peace Prize (d. 1971)
August 12 – Alexei Nikolaevich, Tsarevich of Russia (d. 1918)
Charles "Buddy" Rogers, American actor and jazz musician (d. 1999)
Jonathan Hole, American actor (d. 1998)
Minoru Genda, Japanese aviator, naval officer, and politician (d. 1989)
Wendell Meredith Stanley, American chemist, Nobel Prize laureate (d. 1971)
Mary Cain, American newspaper editor and politician (d. 1984)
Leopold Nowak, Austrian musicologist (d. 1991)
August 19 – George de la Warr, British alternative physician (d. 1969)
August 21 – Count Basie, American musician and bandleader (d. 1984)
Deng Xiaoping, Chinese leader (d. 1997)
Jay Novello, American actor (d. 1982)
Viscountess Furness, born Thelma Morgan, American socialite twin (d. 1970)
Gloria Morgan Vanderbilt, born Gloria Morgan, American socialite twin (d. 1965)
William Primrose, Scottish violist (d. 1982)
August 24 – Ida Cook, English campaigner for Jewish refugees, and romantic novelist as Mary Burchell (d. 1986)
Christopher Isherwood, English writer (d. 1986)
Georgia Schmidt, American actress (d. 1997)
August 28 – Secondo Campini, Italian jet pioneer (d. 1980)
August 29 – Werner Forssmann, German physician, recipient of the Nobel Prize in Physiology or Medicine (d. 1979)
September 9 – Feroze Khan, Pakistani field hockey player (d. 2005)
September 12 – Lou Moore, American race car driver and team owner (d. 1956)
September 13 – Alberta Williams King, American civil rights champion, wife of Martin Luther King, Sr., and mother of Martin Luther King, Jr. (Shot) (d. 1974)
September 14 – Richard Mohaupt, German composer and Kapellmeister (d. 1957)
September 19 – Elvia Allman, American actress (d. 1992)
September 29 – Greer Garson, English actress (d. 1996)
Irene Craigmile Bolam, American Amelia Earhart look-alike/believed alias (d. 1982)
A. K. Gopalan, Indian communist leader (d. 1977)
October 2 – Graham Greene, English author (d. 1991)
October 3 – Charles J. Pedersen, American chemist, Nobel Prize laureate (d. 1989)
October 9 – Wally Brown, American actor and comedian (d. 1961)
October 18 – Haim Shirman, Russian-born Israeli professor of medieval Spanish Jewish poetry (d. 1981)
October 20 – Tommy Douglas, Canadian politician (d. 1986)
October 23 – Harvey Penick, American golfer (d. 1995)
October 25 – Vladimir Peter Tytla, American animator (d. 1968)
November 1 – Laura La Plante, American silent film actress (d. 1996)
November 2 – Hugh Lygon, English aristocrat (d. 1936)
November 4 – Tadeusz Żyliński, Polish technician and textilist (d. 1967)
J. H. C. Whitehead, British mathematician (d. 1960)
Alger Hiss, American lawyer, government official, author and lecturer (d. 1996)
November 12 – Jacques Tourneur, French director (d. 1977)
Dick Powell, American actor and singer (d. 1963)
Michael Ramsey, Archbishop of Canterbury (d. 1988)
November 16 – Nnamdi Azikiwe, President of Nigeria (d. 1996)
November 18 – Masao Koga, Japanese composer (d. 1978)
November 22 – Louis Néel, French physicist, Nobel Prize laureate (d. 2000)
Lillian Copeland, American athlete (d. 1964)
Toni Ortelli, Italian composer and alpinist (d. 2000)
November 30 – Clyfford Still, American painter (d. 1980)
December 4 – Albert Norden, German politician (d. 1982)
December 6 – Ève Curie, French author (d. 2007)
December 7 – Clarence Nash, American voice actor (d. 1985)
December 12 – Baron Nicolas de Gunzburg, French-born magazine editor and socialite (d. 1981)
December 18 – George Stevens, American film director (d. 1975)
December 20 – Rambai Barni Svastivatana, Queen consort of King Prajadhipok of Siam. (d. 1984)
Joseph M. Juran, American engineer and philanthropist (d. 2008)
Herbert D. Riley, United States Navy admiral (d. 1973)
Gerhard Herzberg, German-born chemist, Nobel Prize laureate (d. 1999)
Flemmie Pansy Kittrell, American nutritionist (d. 1980)
December 26 – Alejo Carpentier, Cuban writer (d. 1980)
December 27 – Linwood G. Dunn, special effects artist (d. 1998)
Dmitri Kabalevsky, Russian composer (d. 1987)
David M. Shoup, American general (d. 1983)
Bernard Castro, Italian inventor (d. 1991)
Tevfik Esenç, Turkish-born last speaker of the Ubykh language (d. 1992)
Soeman Hs, Indonesian author and educator (d. 1999)
January 2 – James Longstreet, Confederate Civil War general (b. 1821)
January 7 – Emmanuel Rhoides, Greek writer (b. 1836)
January 10 – Jean-Léon Gérôme, French painter (b. 1824)
January 17 – Sir Henry Keppel, British admiral (b. 1809)
February 4 – Rudolf Maison, German sculptor (b. 1854)
February 8 – Alfred Ainger, English biographer (b. 1837)
February 15 – Mark Hanna, United States Senator from Ohio (b. 1837)
February 22 – Leslie Stephen, English writer and critic (b. 1832)
Alfred von Waldersee, German Army marshal (b. 1832)
John Lowther du Plat Taylor, British founder of the Army Post Office Corps (b. 1829)
March 17 – Prince George, Duke of Cambridge, grandson of King George III (b. 1819)
March 18 – William Elbridge Sewell, American naval officer and Governor of Guam (b. 1851)
April 5 – Tom Allen, British boxing champion (b. 1840)
April 10 – Queen Isabella II of Spain (b. 1830)
April 13 – Stepan Makarov, Russian admiral (killed in action) (b. 1849)
May 1 – Antonín Dvořák, Czech composer (b. 1841)
May 6 – Franz von Lenbach, German painter (b. 1836)
May 7 – Manuel Candamo, Peruvian politician, 30th President of Peru (b. 1841)
May 8 – Eadweard Muybridge, English photographer and motion picture pioneer (b. 1830)
May 10 – Henry Morton Stanley, Welsh explorer and journalist (b. 1841)
May 19 – Auguste Molinier, French historian (b. 1851)
June 3 – Vincent Tancred, South African cricketer (b. 1875)
June 4 – George Frederick Phillips, Canadian-born military hero (b. 1862)
June 12 – Camille of Renesse-Breidbach, Belgian Count (b. 1836)
June 16 – Nikolay Bobrikov, Russian soldier and politician, Governor-General of Finland (b. 1839)
June 22 – Karl Ritter von Stremayr, former Prime Minister of Austria (b. 1832)
July 1 – George Frederic Watts, British symbolist painter and sculptor (b. 1817)
July 3 – Theodor Herzl, Austrian founder of Zionism (b. 1860)
July 6 – Abai Qunanbaiuli, Kazakh poet (b. 1845)
July 14 – Paul Kruger, President of the South African Republic. (b. 1825)
July 15 – Anton Chekhov, Russian writer (b. 1860)
July 26 – Henry Clay Taylor, American admiral (b. 1845)
August 6 – Eduard Hanslick, Austrian music critic (b. 1825)
Wilgelm Vitgeft, Russian admiral (killed in action) (b. 1847)
Pierre Waldeck-Rousseau, French statesman, 68th Prime Minister of France (b. 1846)
Kawamura Sumiyoshi, Japanese admiral (b. 1836)
William Renshaw, British tennis player (b. 1861)
August 16 – Colonel Prentiss Ingraham, American author of dime fiction (b. 1843)
August 22 – Kate Chopin, American author (b. 1850)
August 25 – Henri Fantin-Latour, French painter (b. 1836)
August 29 – Ottoman Sultan Murad V (b. 1840)
September 22 – Wilson Barrett, English actor (b. 1846)
September 24 – Niels Ryberg Finsen, Icelandic/Faroese/Danish physician and scientist (b. 1860)
Lafcadio Hearn, American-Japanese author (b. 1850)
John F. Stairs, Canadian businessman and statesman (b. 1848)
Frédéric Bartholdi, French sculptor (b. 1834)
Laurence Hope, English poet (b. 1865)
October 15 – George, King of Saxony (b. 1832)
October 21 – Isabelle Eberhardt, Swiss-Algerian explorer (b. 1877)
October 26 – Princess Srivilailaksana The Princess of Suphanburi daughter of King Rama V and Pae Bunnag (b.1868)
November 28 – Fanny Janauschek, Czech actress (b. 1829)
Physics – The Lord Rayleigh
Chemistry – Sir William Ramsay
Physiology or Medicine – Ivan Petrovich Pavlov
Literature – Frédéric Mistral and José Echegaray
Peace – Institut de Droit International
1904 (MCMIV) was a leap year starting on Friday (dominical letter CB) of the Gregorian calendar and a leap year starting on Thursday (dominical letter DC) of the Julian calendar, the 1904th year of the Common Era (CE) and Anno Domini (AD) designations, the 904th year of the 2nd millennium, the 4th year of the 20th century, and the 5th year of the 1900s decade. As of the start of 1904, the Gregorian calendar was 13 days ahead of the Julian calendar, which remained in localized use until 1923.