1661 was a common year starting on a Saturday in the Gregorian calendar, and a common year starting on a Tuesday in the Julian calendar.

Events 
January 6 – The fifth monarchy men unsuccessfully attempt to seize control of London. George Monck's regiment defeats them.
 January 30 – The body of Oliver Cromwell is subjected to a posthumous execution.
 February 5 – The Shunzhi Emperor of the Qing Dynasty of China dies and is succeeded by his son the Kangxi Emperor.
 February 14 – George Monck’s regiment becomes The Lord General's Regiment of Foot Guards (which later becomes Coldstream Guards)
April 23 – King Charles II of England, Scotland, Ireland crowned in Westminster Abbey. This is his second crowning.
April 28 – The University of Santo Tomas in Manila opens. It is Asia's first University.
 June 30 – The first Earl of Argyle is executed at the Mercat Cross in Edinburgh for treason.
 August 6 – Portugal and the Dutch Republic sign the treaty of The Hague, whereby New Holland in present-day Brazil is ceded to Portugal.
 December 30 – Drottningholm Castle in Stockholm is destroyed by fire.

 Dutch rule ends in Taiwan.
 First modern bank notes issued in Stockholm, Sweden

Births 

 January 30 – Charles Rollin, French historian (d. 1741)
 March 25 – Paul de Rapin, French historian (d. 1725)
 April 16 – Charles Montagu, 1st Earl of Halifax, English poet and statesman (d. 1715)
 May 25 – Claude de Buffier, French philosopher and historian (d. 1737)
 June 6 – Giacomo Antonio Perti, Italian composer (d. 1756)
 June 9 – Tsar Feodor III of Russia (d. 1682)
 July 20 – Pierre Le Moyne, French founder of the Louisiana colony (d. 1706)
 September 2 – Georg Boehm, German organist (d. 1733)
 October 11 – Melchior de Polignac, French diplomat (d. 1742)
 November 1 – Florent Carton Dancourt, French dramatist and actor (d. 1725)
 November 4 – Karl Philip, Elector Palatine (d. 1742)
 November 6 – King Charles II of Spain (d. 1700)
 November 15 – Christoph Graffenried, Swiss settler in America (d. 1743)
 November 28 – Edward Hyde, 3rd Earl of Clarendon, Governor of New York and New Jersey (d. 1723)
 December 5 – Robert Harley, 1st Earl of Oxford and Mortimer, English statesman (d. 1724)
 December 18 – Christopher Polhem, Swedish scientist and inventor (d. 1751)

Deaths

 January 19 – Thomas Venner, Fifth Monarchist
 February 2 – Lucas Holstenius, German humanist (b. 1596)
 February 5 – Shunzhi Emperor of China (b. 1638)
 March 1 – Richard Zouch, English jurist (b. 1590)
 March 9 – Cardinal Mazarin, French cardinal and statesman (b. 1602)
 April 4 – Alexander Leslie, 1st Earl of Leven, Scottish soldier (b. 1580)
 April 7 – William Brereton, English soldier and politician (b. 1604)
 May 27 – Archibald Campbell, 1st Marquess of Argyll, Scottish dissenter (b. 1607)
 August 7 – Jin Shengtan, Chinese editor, writer and critic (b. 1608)
 August 16 – Thomas Fuller, English churchman and historian (b. 1608)
 August 29 – Louis Couperin, French composer and organist (b. 1626)
 September 11 – Jan Fyt, Flemish painter (b. 1611)
 October 4 – Jacqueline Pascal, French child prodigy and sister of Blaise Pascal (b. 1625)
 October 28 – Agustin Moreto y Cavana, Spanish playwright (b. 1618)
 November 19 – Brian Walton, English clergyman and scholar (b. 1600)
 December 29 – Antoine Gerard de Saint-Amant, French poet (b. 1594)