The Battle of the Koromokina Lagoon was fought between the United States Marine Corps and Imperial Japanese Army forces on Bougainville Island. It took place on 7–8 November 1943 during the Bougainville campaign of the Pacific War.

The Bougainville campaign was a series of land and naval battles of the Pacific campaign of World War II between Allied forces and the Empire of Japan, named after the island of Bougainville. It was part of Operation Cartwheel, the Allied grand strategy in the South Pacific.