The battle of Buna–Gona was part of the New Guinea campaign in the Pacific Theatre during World War II. It followed the conclusion of the Kokoda Track campaign and lasted from 16 November 1942 until 22 January 1943. The battle was fought by Australian and United States forces against the Japanese beachheads at Buna, Sanananda and Gona. From these, the Japanese had launched an overland attack on Port Moresby. In light of developments in the Solomon Islands campaign, Japanese forces approaching Port Moresby were ordered to withdraw to and secure these bases on the northern coast. Australian forces maintained contact as the Japanese conducted a well-ordered rearguard action. The Allied objective was to eject the Japanese forces from these positions and deny them their further use. The Japanese forces were skillful, well prepared and resolute in their defence. They had developed a strong network of well-concealed defences.

The New Guinea campaign of the Pacific War lasted from January 1942 until the end of the war in August 1945. During the initial phase in early 1942, the Empire of Japan invaded the Territory of New Guinea on 23 January and Territory of Papua on 21 July and overran western New Guinea beginning on 29 March. During the second phase, lasting from late 1942 until the Japanese surrender, the Allies—consisting primarily of Australian forces—cleared the Japanese first from Papua, then New Guinea, and finally from the Dutch colony.