Shirley, William (1694–1771), a British official in the American colonies. He was governor of Massachusetts, 1741–49 and 1753–56. During King George's War, Shirley planned the capture in 1745 of the French fort of Louisbourg (on Cape Breton Island off Nova Scotia), Britain's first and most decisive victory. With the money Massachusetts received from Parliament for its war expenses, Shirley was able to give the colony a sound currency for the first time in decades. In the French and Indian War, he led an unsuccessful expedition to Niagara against the French (1755) and was briefly commander of all British forces in America. He was governor of the Bahama Islands, 1761–67.