1924 1925 1926 - 1927 - 1928 1929 1930
1890s 1900s 1910s - 1920s - 1930s 1940s 1950s
- January 1 – The Cristero War erupts in Mexico when pro-Church rebels attack the government, which had banned the Catholic faith.
- January 7 – The first transatlantic telephone call is made from New York City to London.
- January 9 – A military rebellion is crushed in Lisbon.
- January 15 – Teddy Wakelam gives the first sports commentary on BBC Radio.
- January 19 – Britain sends troops to China.
- January 30 – Right-wing veterans and the Republican Schutzbund clash in Schattendorf, Burgenland, Austria. One man and a child are killed by gunshots (see July 15).
- February 12 – The first British troops land in Shanghai.
- February 14 – An earthquake in Yugoslavia kills 700.
- February 19 – A general strike in Shanghai protests the presence of British troops.
- February 23 – The U.S. Federal Radio Commission (later renamed the Federal Communications Commission) begins to regulate the use of radio frequencies.
- March 4 – A diamond rush in South Africa includes trained athletes that have been hired by major companies to stake claims.
- March 7 – A Richter Scale 7.6 magnitude earthquake kills at least 2,925 at Toyooka and Mineyama area, western Honshu, Japan.
- March 10 – Albania mobilizes in case of an attack of Yugoslavia.
- March 11
- March 13 – Fritz Lang's culturally influential Metropolis (film) debuts in Germany.
- April 1 – The first female police officers are hired in Dresden.
- April 5 – In Britain, the Trade Disputes Act forbids strikes of support.
- April 7 – Bell Telephone Co. transmits an image of Commerce Secretary Hoover which becomes the first successful long distance demonstration of television.
- April 12
- The Royal and Parliamentary Titles Act 1927 renames the United Kingdom of Great Britain and Ireland to the United Kingdom of Great Britain and Northern Ireland. The change acknowledges that the Irish Free State is no longer part of the Kingdom.
- Kuomintang troops kill number of communist-supporting workers in Shanghai. The incident is called the April 12 Incident, or Shanghai Massacre. The 1st United Front between the Nationalists and Communist ends, and the Civil War lasting until 1949 begins.
- April 18 – The Kuomintang sets up a government in Nanking, China.
- April 21 – A banking crisis hits Japan.
- April 22 – May 5 – The Great Mississippi Flood of 1927 affects 700,000 people in the greatest national disaster in U.S. history at that time.
- April 27 – The Carabineros de Chile (Chilean national police force and gendarmery) are created.
- April 30 – Cardiff City wins the FA Cup after beating Arsenal 1-0 at Wembley Stadium.
- May – Philo Farnsworth transmits first experimental electronic television pictures.
- May 7 – Civil war ends in Nicaragua.
- May 9 – The Australian Parliament first convenes in Canberra.
- May 11 – The Academy of Motion Picture Arts and Sciences, the "Academy" in "Academy Awards," is founded.
- May 12 – The British police raid the office of the Soviet trade delegation.
- May 13 – George V proclaims the change of his title from King of the United Kingdom of Great Britain and Ireland to King of Great Britain and Ireland.
- May 14 – The ship Cap Arcona is launched at Blohm & Voss shipyard, in Hamburg.
- In the U.S., the University of Chicago's local collegiate organization, Phi Sigma, becomes incorporated under the laws of the State of Illinois as Eta Sigma Phi, the National Honorary Classical Fraternity.
- May 17 – Army aviation pioneer Major Harold Geiger dies in the crash of his Airco DH.4 de Havilland plane, at Olmstead Field, Pennsylvania.
- May 18 – Bath School disaster: Bombings result in 45 deaths, mostly children, in Bath Township, Michigan.
- May 20 – Saudi Arabia becomes independent of the United Kingdom (Treaty of Jedda).
- May 20-21 – Charles Lindbergh makes the first solo non-stop trans-Atlantic flight, from New York to Paris.
- May 22 – An 8.6 magnitude earthquake in Xining, China kills 200,000.
- May 23 – Nearly 600 members of the American Institute of Electrical Engineers and the Institute of Radio Engineers view the first live demonstration of television at the Bell Telephone Building in New York.
- May 24 – Britain severs diplomatic relations with the Soviet Union because of revelations of espionage and underground agitation.
- June 4 – Yugoslavia severs diplomatic relations with Albania.
- June 7 – Peter Voikov, Soviet ambassador to Warsaw, is assassinated.
- June 9 – The Soviet Union executes 20 British for alleged espionage.
- June 13
- July 10 – Kevin O'Higgins, vice president of the Irish Free State, is assassinated in Dublin.
- July 11 – An earthquake strikes Palestine, killing around 300. The effects are especially severe in Nablus, but damage and fatalities are also reported in many areas of Palestine and Trans-Jordan such as Amman, Salt and Lydda.
- July 15 – 85 protesters and 5 policemen are dead after left-wing protesters and the Austrian police clash in Vienna. More than 600 people are injured. See Massacre of July 15, 1927.
- July 22 – The Italian football club A.S. Roma is founded.
- July 24 – The Menin Gate war memorial is unveiled at Ypres, Belgium.
- August 1 – The Communist Chinese People's Liberation Army is formed during the Nanchang Uprising.
- August 2 – U.S. President Calvin Coolidge announces, "I do not choose to run for President in 1928."
- August 7 – The Peace Bridge opens between Fort Erie, Ontario and Buffalo, New York.
- August 22 – In Hyde Park, London, 200 people demonstrate against the sentence of Italian immigrant anarchists Sacco and Vanzetti.
- August 23 – Sacco and Vanzetti are executed.
- August 24-25 – A hurricane hits the Atlantic shore of Canada, causing massive damage and at least 56 deaths.
- August 26 – Paul R. Redfern leaves Brunswick, Georgia, flying his Stinson Detroiter "Port of Brunswick" to attempt a solo non-stop flight to Rio de Janeiro, Brazil. He later crashes in the Venezuela jungle (the crash site is never located).
- September 7 – The University of Minas Gerais is founded in Brazil.
- September 14 – An underwater earthquake in Japan kills over 100 people.
- September 18 – The Columbia Phonographic Broadcasting System (later known as CBS) is formed and goes on the air with 47 radio stations.
- September 27 – 79 are killed and 550 are injured in the East St. Louis Tornado, the 2nd costliest and at least 24th deadliest tornado in U.S. history.
- October 9 – The Mexican government crushes a rebellion in Vera Cruz.
- October 27 – The Italian steamer ship Principessa Mafalda capsizes off Porto Seguro, Brazil; at least 314 are killed.
- October 27 – Queen Wilhelmina of the Netherlands opens the Meuse-Waal Canal in Nijmegen.
- October 28 – Pan American Airways' first flight takes off from Key West, bound for Havana.
- 3-4 November – Floods devastating Vermont incur the "worst natural disaster in the state's history".
- November 4 – Frank Heath and his horse Gypsy Queen return to Washington, D.C., having completed a 2-year journey of 11,356 miles to all 48 states.
- November 10 – Unexplained explosions occur in Canton, Ohio.
- November 12
- November 14 – The Pittsburgh Gasometer Explosion: Three Equitable Gas storage tanks in the North Side of Pittsburgh, Pennsylvania explode, killing 26 people and causing damage estimated between contemporary totals of $4 million and $5 million.
- November 24 – A total solar eclipse occurs over Northern England and Wales.
- December – Communist Party congress condemns all deviation from the general party line in the USSR.
- December 2 – Following 19 years of Ford Model T production, the Ford Motor Company unveils the Ford Model A as its new automobile.
- December 12 – 1,600 people are hospitalized in London after hurting themselves on the icy streets.
- December 15 – Marion Parker, 12, is kidnapped in Los Angeles. Her dismembered body is found on December 19, prompting the largest manhunt to date on the West Coast for her killer, William Edward Hickman, who is arrested on December 22 in Oregon.
- December 17 – The U.S. submarine S-4 is accidentally rammed and sunk by the United States Coast Guard destroyer John Paulding off Provincetown, Massachusetts, killing everyone aboard after several unsuccessful attempts to raise the sub.
- December 27 – Kern and Hammerstein's musical play Show Boat, based on Edna Ferber's novel, opens on Broadway and goes on to become the first great classic of the American musical theatre.
- December 30 – The first Japanese metro line, the Ginza Line in Tokyo, opens.
- January 9 - Houston Stewart Chamberlain, British-born historian and political philosopher (b. 1885)
- February 14 - Fyodor Viktorovich Vinberg, Russian nationalist and journalist (b. 1868)