|Centuries:||17th century – 18th century – 19th century|
|Decades:||1700s 1710s 1720s – 1730s – 1740s 1750s 1760s|
|Years:||1728 1729 1730 – 1731 – 1732 1733 1734|
|1731 by topic:|
|Arts and Sciences|
|Archaeology – Architecture – Art – Literature (Poetry) – Music – Science|
|Canada –Denmark – France – Great Britain – Ireland – Norway – Russia – Scotland –Sweden –|
|Lists of leaders|
|Colonial governors – State leaders|
|Birth and death categories|
|Births – Deaths|
|Establishments and disestablishments categories|
|Establishments – Disestablishments|
|Ab urbe condita||2484|
|British Regnal year||4 Geo. 2 – 5 Geo. 2|
|Chinese calendar||庚戌年 (Metal Dog)
4427 or 4367
— to —
辛亥年 (Metal Pig)
4428 or 4368
|- Vikram Samvat||1787–1788|
|- Shaka Samvat||1653–1654|
|- Kali Yuga||4832–4833|
|Japanese calendar||Kyōhō 16
|Julian calendar||Gregorian minus 11 days|
|Minguo calendar||181 before ROC
|Thai solar calendar||2273–2274|
|Wikimedia Commons has media related to 1731.|
1731 (MDCCXXXI) was a common year starting on Monday (dominical letter G) of the Gregorian calendar and a common year starting on Friday (dominical letter C) of the Julian calendar, the 1731st year of the Common Era (CE) and Anno Domini (AD) designations, the 731st year of the 2nd millennium, the 31st year of the 18th century, and the 2nd year of the 1730s decade. As of the start of 1731, the Gregorian calendar was 11 days ahead of the Julian calendar, which remained in localized use until 1918.
- March 16 – The Treaty of Vienna is signed between the Holy Roman Empire, Great Britain, the Dutch Republic and Spain.
- April 2 – The town of Raynham, Massachusetts in Bristol County is entered as a new town by the governor and court of Massachusetts, New England, America.
- April – British trader Robert Jenkins has his ear cut off by Spanish coast guards in Cuba, casus belli for the War of Jenkins' Ear in 1739.
- Royal Colony of North Carolina Governor George Burrington asks the North Carolina General Assembly to pass an act establishing a town on the Cape Fear River, in what is seen as a political move to shift the power away from the powerful Cape Fear plantation class. The town is laid out in 1733 and incorporated as Wilmington in 1740.
- English Captain Charles Gough rediscovers Gough Island in the South Atlantic.
- Laura Bassi becomes the first official female university teacher on being appointed professor of anatomy at the University of Bologna at the age of 21.
- John Bevis observes the Crab Nebula for the first time in the modern era.
- The Royal Theatre of Mantua (Italy) is built by Ferdinando Galli Bibiena.
- February – Charles Churchill, English poet (d. 1764)
- April 8 – William Williams, Signer of the Declaration of Independence (d. 1811)
- May 8 – Beilby Porteus, Bishop of London and abolitionist (d. 1809)
- June 2 – Martha Washington, First Lady of the United States (d. 1802)
- August – Henry Constantine Jennings, English gambler and collector (d. 1819)
- October 10 – Henry Cavendish, English scientist (d. 1810)
- November 9 – Benjamin Banneker, African-American astronomer and surveyor of the District of Columbia (d. 1806)
- November 15 – William Cowper, English poet (d. 1800)
- December 8 – František Xaver Dušek, Czech composer (d. 1799)
- December 12 – Erasmus Darwin, English scientist and grandfather of Charles Darwin (d. 1802)
- December 28 – José de Viera y Clavijo, Spanish writer
- Nikephoros Theotokis, Greek scholar and theologian (d. 1800)
- Mikiel'Ang Grima – Maltese surgeon (d. 1798)
- January 6 – Étienne François Geoffroy, French chemist (b. 1672)
- January 27 – Bartolomeo Cristofori, Italian maker of musical instruments (b. 1655)
- February 22 – Frederik Ruysch, Dutch physician and anatomist (b. 1638)
- March 5 - Abd al-Ghani al-Nabulsi, Sufi academic (b. 1641
- March 8 – Ferdinand Brokoff, Czech sculptor (b. 1688)
- March 12 – Ernest August, Duke of Schleswig-Holstein-Sonderburg-Augustenburg (b. 1660)
- c. April 24 – Daniel Defoe, English writer (b. 1660)
- May 1 – Johann Ludwig Bach, German composer (b. 1677)
- August 27 – Eudoxia Lopukhina, divorced wife of Peter the Great of Russia (b. 1669)
- December 17 – George Lockhart, writer, spy and politician (duel)
- December 26 – Antoine Houdar de la Motte, French writer (b. 1672)
- December 29 – Brook Taylor, English mathematician (b. 1685)