1808 was a leap year starting on Friday of the Gregorian calendar.
|Centuries:||18th century – 19th century – 20th century|
|Decades:||1770s 1780s 1790s – 1800s – 1810s 1820s 1830s|
|Years:||1805 1806 1807 – 1808 – 1809 1810 1811|
- March 13 – Frederick VI becomes king of Denmark. The next day, Denmark declares war on Sweden.
- March 19 – Charles IV of Spain leaves the throne for his son, Ferdinand VII.
- November 15 – Mahmud II (1808–1839) succeeds Mustafa IV (1807–1808) as sultan of the Ottoman Empire.
- Goethe's Faust: The First Part of the Tragedy is published.
- Barium, calcium, magnesium and strontium are isolated by Humphry Davy in England.
- for more information, see Category:1808 births.
- for more information, see Category:1808 deaths.