The Battle of Caldera Bay, or the Sinking of Blanco Encalada, was a naval engagement fought in the Caldera Bay during the 1891 Chilean Civil War between Balmacedist and Congressional naval forces on 23 April 1891. It involved two Balmacedist torpedo boats of the Almirante Lynch-class, and the Congressional armored frigate Blanco Encalada.

Caldera is a port city and commune in the Copiapó Province of the Atacama Region in northern Chile. It has a harbor protected by breakwaters, being the port city for the productive mining district centering on Copiapó to which it is connected by the first railroad constructed in Chile.