The South West Pacific theatre, during World War II, was a major theatre of the war between the Allies and the Axis. It included the Philippines, the Dutch East Indies (except for Sumatra), Borneo, Australia, its mandate Territory of New Guinea (including the Bismarck Archipelago) and the Solomon Islands' western part. This area was defined by the Allied powers' South West Pacific Area (SWPA) command.
Japanese forces fought primarily against the United States and Australian forces in the South West Pacific theatre. The Philippines, New Zealand, the Netherlands (in the Dutch East Indies), the United Kingdom, and other Allied nations also contributed forces.