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.
After landing on the southeastern tip of the island, the single US infantry regiment of three battalions assigned to the operation undertook a two-pronged advance up the eastern and western coasts.