1825 was a common year.
|Centuries:||18th century – 19th century – 20th century|
|Decades:||1790s 1800s 1810s – 1820s – 1830s 1840s 1850s|
|Years:||1822 1823 1824 – 1825 – 1826 1827 1828|
- January 4 – King Ferdinand I of the Two Sicilies dies and is succeeded by his son Francis I of the Two Sicilies.
- 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 officially succeeds James Monroe as President of the United States.
- July 6 – The Duke of Schleswig-Holstein-Sønderborg-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 became the Royal House of Greece, Denmark and Norway.
- July 30 – Malden Island (an uninhabited island in the central Pacific Ocean) discovered.
- August 6 – Bolivia gains independence from Peru as a republic with the instigation of Simón Bolívar
- August 25 – Uruguay declares independence from Brazil (See Uruguay's independence)
- September 27 – The world's first modern railway, the Stockton and Darlington Railway opens in England.
- October 26 – The Erie Canal opens – passage from Albany, New York to Lake Erie
- December 1 – Nicholas I of Russia succeeds his older brother Alexander I.
- Decembrist Revolt in Russia.
- The first horse-drawn omnibuses established in London
- First roller skates
- Aluminium discovered
- City of Brisbane founded – see History of Brisbane
- The electromagnet was invented by William Sturgeon
- May 2 – Michail Leontievich Bulatov, Russian military