The action of 18 November 1809 was the major engagement of a six-month cruise by a French frigate squadron in the Indian Ocean, during the Napoleonic Wars. The French commander, Commodore Jacques Hamelin, was engaged in commerce raiding across the Bay of Bengal. His squadron achieved local superiority, capturing numerous merchant ships and minor warships. On 18 November 1809, off the Nicobar Islands, three warships (two frigates and a corvette) under Hamelin's command encountered a convoy of three East Indiamen merchant vessels bound for British India, mainly carrying recruits for the army of the East India Company (EIC).

The largest British merchant ship, Windham commanded by John Stewart, took advantage of a disrupted French formation to attack the frigate Manche. The two ships fought for an hour before Manche disengaged and Windham fled. The other two Indiamen declined to join the action and offered only token resistance to the more powerful French warships before surrendering. Windham evaded the French pursuit for five days before also being captured by the French flagship, Vénus.

Hamelin's force began transporting their captured prizes back to the distant French base on Île de France. A month after the battle, the squadron encountered a winter hurricane that heavily damaged several ships. Vénus only survived with the co-operation of the British prisoners she was carrying, including Stewart, who helped bring the ship safely to port. With the ships scattered after the storm, Windham was recaptured by a patrolling British frigate within a few miles of the French island. The other French ships and two East Indiamen successfully reached Île de France. Stewart and his crew were subsequently released in recognition of their assistance during the hurricane.

The action was one of three losses of East Indiamen convoys during 1809, which prompted the British to substantially increase their naval presence in the Indian Ocean during 1810.