The Battle of Wareo was fought by Australian and Japanese forces in New Guinea during the Huon Peninsula campaign of World War II in the later part of 1943. Coming after the capture of Sattelberg by the Allies, the battle took place amidst the Australian advance north towards Sio. The Australians committed elements from four infantry brigades from the Australian 9th Division with supporting elements including artillery, engineers and tank support, while the Japanese force consisted primarily of two depleted infantry regiments from the 20th Division, with limited artillery support.

The Huon Peninsula campaign was a series of battles fought in north-eastern Papua New Guinea in 1943–1944 during the Second World War. The campaign formed the initial part of an offensive that the Allies launched in the Pacific in late 1943 and resulted in the Japanese being pushed north from Lae to Sio on the northern coast of New Guinea over the course of a four-month period. For the Australians, a significant advantage was gained through the technological edge that Allied industry had achieved over the Japanese by this phase of the war, while the Japanese were hampered by a lack of supplies and reinforcements due to Allied interdiction efforts at sea and in the air.