Fort Ticonderoga, formerly Fort Carillon, is a large 18th-century star fort built by the French at a narrows near the south end of Lake Champlain, in northern New York, in the United States. It was constructed by Canadian-born French military engineer Michel Chartier de Lotbinière, Marquis de Lotbinière between October 1755 and 1757, during the action in the "North American theater" of the Seven Years' War, often referred to in the US as the French and Indian War. The fort was of strategic importance during the 18th-century colonial conflicts between Great Britain and France, and again played an important role during the Revolutionary War.

The capture of Fort Ticonderoga occurred during the American Revolutionary War on May 10, 1775, when a small force of Green Mountain Boys led by Ethan Allen and Colonel Benedict Arnold surprised and captured the fort's small British garrison. The cannons and other armaments at Fort Ticonderoga were later transported to Boston by Colonel Henry Knox in the noble train of artillery and used to fortify Dorchester Heights and break the standoff at the siege of Boston.