The Battle of Wau, 29 January – 4 February 1943, was a battle in the New Guinea campaign of World War II. Forces of the Empire of Japan sailed from Rabaul and crossed the Solomon Sea and, despite Allied air attacks, successfully reached Lae, where they disembarked. Japanese troops then advanced overland on Wau, an Australian base that potentially threatened the Japanese positions at Salamaua and Lae. A race developed between the Japanese moving overland, hampered by the terrain, and the Australians, moving by air, hampered by the weather. By the time the Japanese reached the Wau area after a trek over the mountains, the Australian defenders had been greatly reinforced by air. In the battle that followed, despite achieving tactical surprise by approaching from an unexpected direction, the Japanese attackers were unable to capture Wau.

The 2/6th Battalion was an infantry battalion of the Australian Army that served during the Second World War. Raised in October 1939 as part of the all-volunteer Second Australian Imperial Force, the battalion formed part of the 6th Division and was among the first troops raised by Australia during the war. Departing Australia in early 1940, the 2/6th were deployed to the Middle East where in January 1941, it took part in the first action of the war by Australian ground forces, the Battle of Bardia, which was followed by further actions around Tobruk. Later, the 2/6th were dispatched to take part in the Battle of Greece, although they were evacuated after only a short involvement in the campaign. Some members of the battalion subsequently fought on Crete with a composite 17th Brigade battalion, and the battalion had to be re-formed in Palestine before being sent to Syria in 1941–42, where they formed part of the Allied occupation force that was established there in the aftermath of the Syria–Lebanon campaign.