King George's War (1744–1748) is the name given to the military operations in North America that formed part of the War of the Austrian Succession (1740–1748). It was the third of the four French and Indian Wars. It took place primarily in the British provinces of New York, Massachusetts Bay, New Hampshire, and Nova Scotia. Its most significant action was an expedition organized by Massachusetts Governor William Shirley that besieged and ultimately captured the French fortress of Louisbourg, on Cape Breton Island in Nova Scotia, in 1745. In French, it is known as the Troisième Guerre Intercoloniale or Third Intercolonial War.

The War of the Austrian Succession was a European conflict fought between 1740 and 1748, primarily in Central Europe, the Austrian Netherlands, Italy, the Atlantic Ocean and Mediterranean Sea. Related conflicts include King George's War in North America, the War of Jenkins' Ear, the First Carnatic War, and the First and Second Silesian Wars.