The 1777 Siege of Fort Ticonderoga occurred between the 2nd and 6 July 1777 at Fort Ticonderoga, near the southern end of Lake Champlain in the state of New York. Lieutenant General John Burgoyne's 8,000-man army occupied high ground above the fort, and nearly surrounded the defenses. These movements precipitated the occupying Continental Army, an under-strength force of 3,000 under the command of General Arthur St. Clair, to withdraw from Ticonderoga and the surrounding defenses. Some gunfire was exchanged, and there were some casualties, but there was no formal siege and no pitched battle. Burgoyne's army occupied Fort Ticonderoga and Mount Independence, the extensive fortifications on the Vermont side of the lake, without opposition on 6 July. Advance units pursued the retreating Americans.

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.