During World War II, the division was mobilised for war in December 1941 and initially undertook defensive duties in Australia before being deployed to New Guinea in 1943 where they took part in the Salamaua–Lae campaign against the Japanese in 1943–1944, before returning to Australia for rest and reorganisation. In late 1944 they were sent to Bougainville to take part in their final campaign of the war. There they undertook a series of advances across the island before the war came to an end in August 1945.