The Battle of Carillon, also known as the 1758 Battle of Ticonderoga, is fought on July 8, 1758, during the French and Indian War (which is part of the global Seven Years' War).

It is fought near Fort Carillon (now known as Fort Ticonderoga) on the shore of Lake Champlain in the frontier area between the British colony of New York and the French colony of New France.

In the battle, which takes place primarily on a rise about three-quarters of a mile (one kilometer) from the fort itself, a French army of about thirty-six hundred men under General Louis-Joseph de Montcalm and the Chevalier de Levis decisively defeats an overwhelmingly numerically superior force of British troops under General James Abercrombie, which frontally assaults an entrenched French position without using field artillery, a lack that leaves the British and its allies vulnerable and allows the French to win a decisive victory.

The battle is the bloodiest of the war, with over three thousand casualties suffered.

French losses are about four hundred, while the British suffer more than more than two thousand.

Many military historians have cited the Battle of Carillon as a classic example of tactical military incompetence.

Abercrombie, confident of a quick victory, had ignored several viable military options, such as flanking the French breastworks, waiting for his artillery, or laying siege to the fort. Instead, relying on a flawed report from a young military engineer, and ignoring some of that engineer's recommendations, he decided in favor of a direct frontal assault on the thoroughly entrenched French, without the benefit of artillery.

Montcalm, while concerned about the weak military position of the fort, conducted the defense with spirit.

However, due in part to a lack of time, he committed strategic errors in preparing the area's defenses that a competent attacker could have exploited, and he made tactical errors that made the attacker's job easier.

The fort, abandoned by its garrison, will be captured by the British the following year, and it will be known as Fort Ticonderoga (after its location) ever since.

This battle gives the fort a reputation for impregnability that will have an effect on future military operations in the area.

Despite several large-scale military movements through the area, in both the French and Indian War and the American Revolutionary War, this is the only major battle fought near the fort's location.