The Battle of Ty-ho Bay was a significant naval engagement in 1855 involving the United Kingdom and United States against Chinese pirates. The action off Tai O, Hong Kong was to rescue captured merchant vessels, held by a fleet of armed war-junks. British and American forces defeated the pirates in one of the last major battles between Chinese pirate fleets and western navies. It was also one of the first joint operations undertaken by British and American forces.

Tai O is a fishing town, partly located on an island of the same name, on the western side of Lantau Island in Hong Kong. The village name means large inlet, referring to outlet for the waterways merges as it moves through Tai O.