Events of 1731

January–June

• 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.

July–December

Undated

• John Bevis observes the Crab Nebula for the first time.

• 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 later incorporated as Wilmington in 1740.

• The Royal Theatre of Mantua (Italy) is built by Ferdinando Galli Bibiena.

• Benjamin Franklin starts the Library Company of Philadelphia.

Births

• 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

Deaths

• 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 8 – Ferdinand Brokoff, Czech sculptor (b. 1688)

• April 24/26 – 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)