U.S. manufacturer of guns and ammunition who developed the Winchester rifle and made the Winchester Repeating Arms Company a success by the shrewd purchase and improvement of the inventions of other men.

As a young man, Winchester moved to Baltimore and operated a men's furnishing store there until 1848, when he set up a factory in New Haven to manufacture dress shirts. His financial success enabled him, in 1857, to purchase the Volcanic Repeating Arms Company of New Haven, successively reorganized as the New Haven Arms Company, and, in 1867, the Winchester Repeating Arms Company.

B.T. Henry, whom he retained as plant manager and chief gun designer, had designed the lever-action Henry repeating rifle and patented it in 1860. Widely used in the Civil War, it was the forerunner of a long line of Winchester guns, including the famous Model 73, a favourite weapon of the settlers in the American West.

Winchester augmented his line by purchasing the patents of the American Repeating Rifle Company, the Spencer Repeating Rifle Company, and the bolt-action repeating rifle of Benjamin B. Hotchkiss. Winchester was also noted for his philanthropy, particularly to Yale University.