|Centuries:||17th century – 18th century – 19th century|
|Decades:||1710s 1720s 1730s – 1740s – 1750s 1760s 1770s|
|Years:||1739 1740 1741 – 1742 – 1743 1744 1745|
- January 24 – Charles VII Albert becomes Holy Roman Emperor.
- February 16 – Spencer Compton, Earl of Wilmington, becomes Prime Minister of Great Britain.
- February 18 – British attack La Guayra.
- April 13 – The first performance of George Frideric Handel's oratorio Messiah, in Dublin.
- May 17 – Frederick the Great's army defeats Austrians in Chotusitz; later Austria cedes Silesia to Prussia
- May 25 – A battle is fought at Sahay.
- December 2 – The Pennsylvania Journal first appears in print.
- Daniel le Pelley succeeds Nicolas le Pelley as Seigneur of Sark.
- Kingdom of Prussia captures Jihlava.
- Christian Goldbach formulates Goldbach's conjecture.
- Colin Maclaurin publishes his Treatise on Fluxions.
- Anders Celsius proposes the Celsius temperature scale.
- James Bradley succeeds Edmond Halley as Astronomer Royal.
- Henry Fielding publishes Joseph Andrews.
- John Carteret, 2nd Lord Carteret becomes Secretary of State for the Northern Department.
- Rigging of Chippenham by-election causes a political scandal.
- William Pulteney created as 1st Earl of Bath.
- Robert Walpole was elevated to the peerage and thus moved from the House of Commons to the House of Lords, (see February 16, above).
- University of Erlangen is founded.
- Lopukhina Conspiracy at the Russian court.
- Molde in Norway becomes a city.
- Construction starts on the Foundling Hospital in London.
- Eisenach builds its Stadtschloss (city castle).
- In Peru, Juan Santon takes the name Atahualpa II and begins an ill-fated rebellion against the Spanish rule
- Afghan tribes unite as a monarchy.
- for more information, see Category:1742 births.
- for more information, see Category:1742 deaths.