The Battle of Caishi (Chinese: 采石之戰, approximately ts'eye-shee) was a major naval engagement of the Jin–Song Wars of China that took place on November 26–27, 1161. It ended with a decisive Song victory, aided by their use of gunpowder weapons.

Soldiers under the command of Wanyan Liang, the emperor of the Jurchen-led Jin dynasty, tried to cross the Yangzi River to attack the Southern Song dynasty.

Chen Kangbo, prime minister of the Song dynasty, was chief military strategist and commanded the navy. Yu Yunwen, a civil official, commanded the defending Song army. The paddle-wheel warships of the Song fleet, equipped with trebuchets that launched incendiary bombs made of gunpowder and lime, decisively defeated the light ships of the Jin navy.