Events of 1671

• April - Battle of Saraighat: The Ahom general Lachit Borphukan defeats the Mughal forces on the outskirts of present day Guwahati, of then sovereign Assam.
• May 9 - Thomas Blood, disguised as a clergyman, attempts to steal the Crown Jewels from the Tower of London. He is immediately caught because he is too drunk to run with the loot. He is later condemned to death and then mysteriously pardoned and exiled by King Charles II.
• June 22 - The Ottoman Empire declares war on Poland.

July - December

• December - The first Seventh Day Baptist church in America is founded at Newport, Rhode Island.

Births

• January 11 - François-Marie, 1st duc de Broglie, French military leader (d. 1745)
• February 26 - Anthony Ashley-Cooper, 3rd Earl of Shaftesbury, English politician and philosopher (d. 1713)
• March 7 - Rob Roy MacGregor, Scottish folk hero (d. 1734)
• April 6 - Jean-Baptiste Rousseau, French poet (d. 1741)
• April 21 - John Law, Scottish economist (d. 1729)
• May 24 - Gian Gastone de' Medici, Grand Duke of Tuscany (d. 1737)
• June 8 - Tomaso Albinoni, Italian composer (d. 1751)
• June 11 - Colley Cibber, English poet (d. 1757)
• July 14 - Jacques D'Allonville, French astronomer and mathematician (d. 1732)
• October 1 - Guido Grandi, Italian mathematician (d. 1742)
• October 11 - King Frederick IV of Denmark (d. 1730)

Deaths

• January 6 - Dubhaltach Mac Fhirbhisigh (b. 1643)
• April 30 - Petar Zrinski, Croatian Ban (title) and nobleman (b. 1621)
• April 30 - Fran Krsto Frankopan, Croatian poet and nobleman (b. 1643)
• March 31 - Anne Hyde, wife of the future James II of England (b. 1637)
• May 5 - Edward Montagu, 2nd Earl of Manchester, English politician (b. 1602)
• June 25 - Giovanni Battista Riccioli, Italian astronomer (b. 1598)
• July 14 - Méric Casaubon, English classical scholar (b. 1599)
• October 26 - Sir John Gell, 1st Baronet, English politician (b. 1593)
• November 12 - Thomas Fairfax, 3rd Lord Fairfax of Cameron, English Civil War general (b. 1612)
• December 28 - Johann Friedrich Gronovius, German classical scholar (b. 1611)

In Fiction

• On Heroes, Hiro Nakamura is transported back to this year at the end of season 1, and part of season 2, in Japan.