| 1730–1807 | UK [newspapers] | The Daily Advertiser is launched in London, England. With its dependence on advertisements, this may be regarded as the first modern newspaper. |
| 1799–1825 | [maths] | The French mathematician and physicist Pierre-Simon Laplace publishes the five-volume Traité de mécanique céleste/Celestial Mechanics, which applies calculus to the motions of celestial bodies and Isaac Newton's theories of the Solar System to show how its stability is implicit in the law of gravitation. |
| c. 1800 | Europe [industrialization] | Belgian textile manufacturer Lieven Bauwens smuggles a Crompton spinning mule out of England, spreading the Industrial Revolution in the textile industry from Britain to the rest of Europe. |
| 1800 | England [astronomy] | German-born English astronomer William Herschel discovers the existence of infrared solar rays. |
| 1800 | USA [family planning] | The birth rate in the USA is over seven per woman, which is the highest in the world. |
| 1800 | USA [clothing and fashion] | The first shoes in the USA designed specifically for the left and right feet are made by shoemaker William Young, in Philadelphia, Pennsylvania. |
| 1800 | Germany [orchestral music] | The German composer Ludwig van Beethoven completes his Symphony No. 1 in C major (Opus 21). |
| 1800 | England [painting] | The English artist George Stubbs paints Hambletonian, Rubbing Down. |
| 1800 | Germany [poetry] | The German writer Novalis (pseudonym of Friedrich Leopold, Baron von Hardenberg) publishes the prose lyrics ‘Hymnen an die Nacht’/‘Hymns to the Night’. |
| 1800–1850 | USA [consumer products] | A revolution in retail and wholesale trade occurs: specialization transforms the urban retail market, replacing the general store with individual stores for hardware, groceries, dry goods, furnishing, books, tobacco, and so on. Cash-only sales policies are instituted around 1806. |
| 1800 | world, Europe [statistics and demography] | The population of the world is estimated at 870 million, with over 20% of people living in Europe. |
| 1800 | UK [statistics and demography] | The population of England and Wales is an estimated 8.7 million, up from just over 5 million in 1700. |
| 1800 | USA [statistics and demography] | US census data show a 35.1% increase in the population, which has climbed to 5.3 million since 1790. |
| 1800 | Italy [technology] | Italian physicist Alessandro Volta invents the voltaic pile made of discs of silver and zinc – the first electric battery. |
| c. 1800 | Europe [women's rights] | Schoolgirls in Europe are deprived of food, exercise, and fresh air to achieve the fashionable look of pallor and thinness. |
| 17 January 1800 | France [treaties] | The Treaty of Montluçon ends royalist disaffection in the Vendée, western France, and releases troops for a new French offensive in Europe. |
| 14 March 1800 | Rome [administration] | The Italian cardinal Luigi Chiaramonti, backed by the influential French cardinal Jean Maury, is elected as Pope Pius VII. |
| 14 June 1800 | France, Austria-HM, Italy [French Revolutionary Wars (1792–1801)] | French forces under Napoleon Bonaparte defeat the Austrians under Baron Michel Melas at the Battle of Marengo, northwest Italy, ensuring the French reconquest of Italy. |
| November 1800 | USA [elections] | In the US presidential election, the Republicans Thomas Jefferson and Aaron Burr each receive 73 electoral votes. Federalists John Adams and Charles Pinckney secure 65 and 64 votes respectively. As stipulated by the US Constitution, the election goes to the House of Representatives, where Jefferson is elected president. |
| 25 December 1800 | UK [everyday life] | King George III's wife, Queen Charlotte, introduces the Christmas tree to the British court. |