The Battle of Arundel Island was fought from 27 August – 21 September 1943, primarily between United States Army and Imperial Japanese Army forces on Arundel Island during the New Georgia campaign in the Pacific War. The battle took place towards the end of the campaign after the capture of Munda airfield and mopping up operations in western New Georgia had resulted in the Japanese evacuation of mainland New Georgia. The US high command decided to occupy the island so that it could be used as a base for artillery to fire on the main Japanese troop concentration on Kolombangara.

The New Georgia campaign was a series of land and naval battles of the Pacific Theater of World War II between Allied forces and the Empire of Japan. It was part of Operation Cartwheel, the Allied strategy in the South Pacific to isolate the Japanese base around Rabaul. The campaign took place in the New Georgia Islands in the central Solomon Islands and followed the Allied capture of the Russell Islands. The main fighting took place on New Georgia itself, although significant actions also took place around the island chain throughout the campaign.