Events of 1825

January–March

• January 4 – King Ferdinand I of the Two Sicilies is succeeded by his son Francis I of the Two Sicilies.

• February 3 – Vendsyssel-Thy, once part of the Jutland peninsula that formed westernmost Denmark, becomes an island after a flood drowns its 1 km wide isthmus.

• February 9 – After no presidential candidate receives a majority of electoral votes, the United States House of Representatives elects John Quincy Adams President of the United States.

• February 10 – Simón Bolívar gives up his title of dictator of Peru and takes the alternative title of Liberator.

• February 12 – The Creek cede the last of their lands in Georgia to the United States government, and migrate west.

• March 4 – John Quincy Adams succeeds James Monroe as [President of the United States].

April–June

• April 17 – Charles X of France recognizes Haiti, 21 years after it expelled the French following the successful Haitian Revolution, and demands the payment of 150 million gold francs, 30 million of which Haiti must finance through France itself, as down payment.

July–September

• July 6 – The Duke of Schleswig-Holstein-Sonderburg-Beck gains possession of Glücksburg and changes his title to Friedrich Wilhelm, Duke of Schleswig-Holstein-Sonderburg-Glücksburg. The line of Schleswig-Holstein-Sonderburg-Glücksburg later becomes the Royal House of Greece, Denmark and Norway.

• July 14 – The Jefferson Literary and Debating Society is founded by 16 disgruntled members of the now-defunct Patrick Henry Society in Room 7, West Lawn, of the University of Virginia.

• July 18 – Uruguay declares independence from Brazil (see Uruguay's independence).

• July 30 – Malden Island (an uninhabited island in the central Pacific Ocean) is discovered.

Opening of the Stockton and Darlington Railway

• August 6 – Bolivia gains its independence from Spain as a republic with the instigation of Simón Bolívar.

• September – The Lady Margaret Boat Club is founded by 12 members of St John's College, Cambridge.

• September 25 – General Hendrik Merkus de Kock lifts the siege of Jogjakarta, the first major action of the Java War.

• September 27 – The world's first modern railway, the Stockton and Darlington Railway, opens in England.

October–December

• October 7 – The Miramichi Fire breaks out in New Brunswick.

• October 26 – The Erie Canal opens, providing passage from Albany, New York to Buffalo and Lake Erie.

• December 1 – Nicholas I of Russia succeeds his older brother Alexander I.

• The Decembrist Revolt breaks out in Russia, but is thoroughly suppressed.

Undated

• The first horse-drawn omnibuses established in London.

• The first roller skates are invented.

• Aluminium is discovered.

• The City of Brisbane is founded (see History of Brisbane).

• Estimation: London becomes the largest city of the world, taking the lead from Beijing.

• The Panic of 1825 is the first modern stock market crash in London.

• Artisans and skilled mechanics receive a right to leave Britain.

• Trade unions become tolerated in England.

• Minh Mang outlaws the teaching of Christianity in Vietnam.

• The United States Postal Service started a dead letter office.

Births

January–June

• January 25 – George Pickett, American Confederate general (d. 1876)

• March 13 – Hans Gude, Norwegian romanticist landscape painter (d. 1903)

• March 22 – Jane Sym, second wife of Canada's second prime minister (d. 1893)

• May 4 – Sir Thomas Henry Huxley, English biologist (d. 1895)

• May 8 – George Bruce Malleson, English officer and author (d. 1898)

July–December

• August 31 – Robert Dunsmuir Scottish industrialist and politician (d. 1889)

• September 11 – Eduard Hanslick, Austrian music critic (d. 1904)

• September 13 William Henry Rinehart, American sculptor (d. 1874)

• September 25 – Joachim Heer, Swiss politician (d. 1879)

• October 10 – Paul Kruger, Boer resistance leader (d. 1904)

• October 25 – Johann Strauss, Junior, Austrian composer (d. 1899)

• November 9 – A.P. Hill, American Confederate general (d. 1865)

• December 2 – Emperor Pedro II of Brazil (d. 1891)

• date unknown – Sher Ali Khan, ruler of Afghanistan (d. 1879)

Deaths

January–June

• January 4 – Ferdinand I of the Two Sicilies (b. 1751)

• May 7 – Antonio Salieri, Italian composer (b. 1750)

• May 19 – Claude Henri de Rouvroy, Comte de Saint-Simon, French politician (b. 1760)

• May 22 – Laskarina Bouboulina, Greek independence fighter (shot)

• May 23 – Ras Gugsa of Yejju, Regent of the Emperor of Ethiopia

July–December

• August 20 – William Waldegrave, 1st Baron Radstock, Governor of Newfoundland (b. 1753)

• November 14 – Jean Paul, German writer (b. 1763)

• December 1 – Alexander I of Russia (disputed; b. 1777)

• December 28 – James Wilkinson, American soldier and statesman

• December 29 – Jacques-Louis David, French painter (b. 1748)