1837 1838 1839 - 1840 - 1841 1842 1843
1810s 1820s 1830s - 1840s - 1850s 1860s 1870s
Events of 1840
- January 3 – One of the predecessor papers of the Herald Sun of Melbourne, Australia, The Port Phillip Herald, is founded.
- January 10 – Uniform penny postage is introduced in the UK.
- January 13 – The steamship Lexington burns and sinks in icy waters, 4 miles off the coast of Long Island; 139 die, only 4 survive.
- January 19 – Captain Charles Wilkes circumnavigates Antarctica, claiming what becomes known as Wilkes Land for the United States.
- January 20
- January 22 – British colonists reach New Zealand, officially founding Wellington.
- February – The Rhodes blood libel is made against the Jews of Rhodes.
- February 5 – The murder of a Capuchin friar and his Greek servant leads to the Damascus affair, a highly publicized case of blood libel against the Jews of Damascus.
- February 6 – The Treaty of Waitangi, granting British sovereignty in New Zealand, is signed.
- February 10 – Queen Victoria of the United Kingdom marries Prince Albert of Saxe Coburg-Gotha.
- February 11 – Gaetano Donizetti's opera La Fille du Regiment premieres in Paris.
- March 1
- April 15 – King's College Hospital opens in Portugal Street, London.
- May 1 – Britain issues the Penny Black, the world's first postage stamp.
- May 6 – The Penny Black, the world's first postage stamp, becomes valid for the pre-payment of postage.
- May 7 – The Great Natchez Tornado: A massive tornado strikes Natchez, Mississippi during the early afternoon hours. Before it is over, 317 people are killed and 109 injured. It is the second deadliest tornado in U.S. history.
- May 21 – New Zealand is declared a British colony.
- July 4 – The Cunard Line's 700-ton wooden paddlewheel steamer RMS Britannia departs from Liverpool, bound for Halifax, Nova Scotia on the first transatlantic passenger cruise.
- July 15 – The Austrian Empire, the United Kingdom of Great Britain and Ireland, the Kingdom of Prussia, and the Russian Empire sign the London Treaty with the Sublime Porte, ruler of the Ottoman Empire.
- July 23 – The Province of Canada is created by the Act of Union.
- August 10 – Fortsas hoax: A number of book collectors gather in Binche, Belgium to attend a non-existent book auction of the late "Count of Fortsas".
- September 10 – Ottoman and British troops bombard Beirut and land troops on the coast to pressure Egyptian Muhammad Ali to retreat from the country.
- September 16 – Joseph Strutt hands over the deeds and papers concerning the Arboretum, which later becomes England's first public park.
- September 30 – The frigate Belle-Poule arrives in Cherbourg, bringing back the remains of Napoléon from Saint Helena to France. He is buried in the Invalides.
- October 7 – Willem II becomes King of the Netherlands.
- November 7 – U.S. presidential election, 1840: William Henry Harrison defeats Martin Van Buren.
- December 7 – David Livingstone leaves Britain for Africa.
- December 7 – The Stockport Viaduct (located in Greater Manchester, England) is completed. It is the largest brick structure in Western Europe.
- December 15 – The corpse of Napoleon is placed in the Hotel des Invalides in Paris.