1756

January–March

• January 16 - The Treaty of Westminster is signed between Great Britain and Prussia, guaranteeing the neutrality of the German province of Hanover, controlled by King George II of Great Britain.
• February 10 - The massacre of the Guaraní rebels in the Jesuit reduction of Caaibaté takes place in Brazil after their leader, Noicola Neenguiru, defies an ultimatum to surrender by 2:00 in the afternoon. Three days earlier, on February 7, Neenguiru's predecessor Sepé Tiaraju had been killed in a brief skirmish. As two o'clock arrives, a combined force of Spanish and Portuguese troops makes an assault on the first of the Seven Towns established as Jesuit missions. Defending their town with cannons made out of bamboo, the Guaraní suffer 1,511 dead, compared to three Spaniards and two Portuguese killed in battle.
• February 14 - The Maratha Navy that has controlled the western coast of India for the Maratha Empire for more than a century, is destroyed in the Battle of Vijaydurg by British attackers fighting for the East India Company. On orders of Royal Navy Admiral Charles Watson, the Royal Navy captures a Maratha ship, sets it on fire, and then floats the burning vessel into the Vijaydurg Port where most of Maratha Admiral Tulaji Angre's ships are anchored. The fire soon spreads to the other ships, destroying one large warship armed with 74 cannon, eight gurabs of 200 tonnes apiece, and sixty galbat ships.
• March 17 - St. Patrick's Day is celebrated in New York City for the first time.

  April–June

• April 1 - Yirmisekizzade Mehmed Said Pasha resigns as Grand Vizier of the Ottoman Empire. He is replaced by Köse Bahir Mustafa Pasha, who had been Grand Vizier from 1752 to 1755.
• April 12 - Seven Years' War: The French invade Menorca, at this time under British control.
• May 18 - Seven Years' War: The Seven Years' War formally begins, when Great Britain declares war on France.
• May 20 - Seven Years' War - Battle of Minorca: The British fleet under John Byng is defeated by the French, under Roland-Michel Barrin de La Galissonière.
• June 20 - A garrison of the British Army in India is imprisoned, in the Black Hole of Calcutta.
• June 22 - The Coup of 1756, an attempted coup d'état planned by Queen Louisa Ulrika of Sweden, to abolish the rule of the Riksdag of the Estates and reinstate absolute monarchy in Sweden with the support of the Hovpartiet, is exposed and subdued.
• June 25 - The Marine Society is founded in London, the world's oldest seafarers' charity.
• June 29 - Seven Years' War - Siege of Fort St Philip at Port Mahon: The British garrison in Menorca surrenders to the French, after two months' siege by Armand de Vignerot du Plessis.

  July–September

• July 30 - Bartolomeo Rastrelli presents the newly built Catherine Palace to Empress Elizabeth and her courtiers in Russia.
• August 14 - Seven Years' War - French and Indian War: Fort Oswego falls to the French.
• August 29 - Frederick II of Prussia invades Saxony, beginning the Seven Years' War on the continent.
• September 2 - Abu l-Hasan Ali I, Bey of Tunis is forcibly removed after 23 years as the ruler of the North African emirate by his cousins, who are avenging the overthrow and execution of their father, Husayn in 1735. Hasan Ali surrenders to the rebels and is imprisoned in Algiers, then executed on September 22 on orders of the new Bey of Tunis, Muhammad I ar-Rashid.

  October–December

• October 1 - Seven Years' War - Battle of Lobositz: Frederick defeats an Austrian army under Marshal Maximilian Ulysses Count Browne.
• October 14 - An "Agreement of Friendship and Trade" is signed by Sultan Osman III and King Frederick V. Denmark appoints an extraordinary representative to the Ottoman Empire.
• November 16 - Thomas Pelham-Holles, the Duke of Newcastle, is forced to resign as Prime Minister of Great Britain after the British surrender of Minorca to the French. The office of Prime Minister remains vacant for eight months as William Pitt and the Duke of Devonshire leading the cabinet.
• December - Seven Years' War - French and Indian War: Militias of the Royal Colony of North Carolina build a fort on the province's western frontier to protect it against natives allied with the French. The fort is named Fort Dobbs in honor of North Carolina Governor Arthur Dobbs, who persuaded the North Carolina legislature to fund the construction a year earlier.
• December 14 - The play Douglas is performed for the first time in Edinburgh, with overwhelming success, in spite of the opposition of the local church presbytery, who summon Alexander Carlyle to answer for having attended its representation. However, it fails in its early promise to set up a new Scottish dramatic tradition.

  Date unknown

• Frederick II of Prussia forces his country's peasants to grow the unpopular and obscure potato.
• The town of Gus-Khrustalny is established in Russia, with the setting up of a crystal glass factory.
• The first chocolate-candy factory begins operations in Germany.
• Leopold Mozart publishes his book on his method for learning to play the violin, Versuch einer gründlichen Violinschule.