January – A fire in Istanbul destroys 10,000 homes.
January 13 – The Treaty of Madrid between Spain and Portugal authorizes a larger Brazil than had the Treaty of Tordesillas of 1494, which originally established the boundaries of the Portuguese and Spanish territories in South America.
March 20 – First number of Samuel Johnson's The Rambler appears.
April – A second fire devastates Istanbul (see January). A third fire later in the year destroys a further 10,000 homes.
April 4 – A small earthquake hits Warrington, England.
May – Riots break out in Paris, fueled by rumors of police abducting children.
July 9 – Traveller Jonas Hanway leaves St. Petersburg to return home via Germany and the Netherlands. Later the same year, Hanway reputedly becomes the first Englishman to use an umbrella (a French fashion).
July 11 – Halifax, Nova Scotia is almost completely destroyed by fire.
July 31 – José I takes over the throne of Portugal from his deceased father, João V. King José Manuel appoints the Marquis of Pombal as his Chief Minister, who then strips the Inquisition of its power.
August 23 – A small earthquake hits Spalding, Lincolnshire, England.
September 30 – A small earthquake hits Northampton, England.
November 11 – A riot breaks out in Lhasa, Tibet, after the murder of the regent of Tibet.
November 18 – Westminster Bridge is officially opened in London.
March 25 - Upon his death, Frederick I of Sweden is succeeded as king by Adolf Frederick.
March 31 – Frederick, Prince of Wales dies in London and is succeeded by his son, the future George III of the United Kingdom, as heir-apparent to the British throne and Prince of Wales.His mother Augusta of Saxe-Gotha becomes Dowager Princess of Wales.
May 11 – The Pennsylvania legislature grants a charter to Benjamin Franklin and Dr. Thomas Bond for the establishment in Philadelphia of the first hospital in the Colonies.
July 28 – Kingdom of Kartli defeats a large army of Tabriz Khanate under Erekle II in the Battle of Kirkhbulakh
July 31 – Fire destroys 1,000 houses in Stockholm.
August 13 – The Academy and College of Philadelphia, predecessor to the private University of Pennsylvania, opens its doors, with Benjamin Franklin as president.
September 13 – Kalvária Banská Štiavnica in the Kingdom of Hungary is completed.
October 27 – The Hōreki period begins in Japan.
December 3 – Battle of Arnee in India (Second Carnatic War): A British East India Company-led force under Robert Clive defeats and routs a much larger Franco-Indian army under the command of Raza Sahib at Arni.
January 30 – The British Empire adopts the Gregorian calendar (to take effect in September).
February 11 – Pennsylvania Hospital, the first hospital in the U.S., is opened.
February 27 – The Virginia Assembly passes a law making maiming a felony, in response to the practice of gouging.
March 23 – The Halifax Gazette, the first Canadian newspaper, is published.
June 6 – Fire destroys 18,000 houses in Moscow.
June 15 – Benjamin Franklin proves that lightning is electricity, using a kite and a key. The experiment however, has since been disputed as actually having taken place. Since Franklin would have been grounded the lightning could have possibly killed him if the experiment took place as told.
September 14 – Great Britain and the British Empire adopt the Gregorian calendar, meaning the Julian date of Wednesday, September 2 is followed by the Gregorian date of Thursday, September 14.
September–December – Jovan Šević leads a group of Serb emigrants from Pomorišje to Kiev.
January 1 – Minimum date value for a datetime field in SQL Server (up to version 2005) due to it being the first full year after Britain adopted the Gregorian calendar.
January 29 – After a month's absence, Elizabeth Canning returns to her mother's home in London and claims that she was abducted. The following criminal trial causes uproar.
March 1 – Sweden adopts the Gregorian calendar by skipping the 11 days difference between it and the Julian calendar and letting February 17 be followed directly by March 1.
March 17 – First official Saint Patrick's Day.
April 5 – The founding charter of the British Museum is enacted.
May 1 – Species Plantarum is published by Linnaeus (adopted by the International Code of Botanical Nomenclature as the formal start date of the scientific classification of plants).
July 7 – Royal assent to the Jewish Naturalization Act: The British Parliament extends citizenship to Jews
October 31 – Virginia Lieut. Gov. Robert Dinwiddie commissions 21-year-old militia Maj. George Washington to dissuade the French from occupying the Ohio Country.