The 55th/53rd Battalion was an infantry battalion of the Australian Army which saw active service during World War II. First formed in 1919 during the demobilisation of the Australian Imperial Force, the battalion was an amalgamation of two other units, the 55th and 53rd Battalions. It was disbanded shortly aftwards and remained off the order of battle until 1937 when it was raised as a part-time unit of the Militia, based in Sydney, New South Wales. In 1941, with the expansion of the Australian Army in response to the growing threat of war in the Pacific, the battalion was split and the 55th and 53rd Battalions reformed separately. In late 1942, however, they were amalgamated once more and together went on to participate in the fighting against the Japanese in New Guinea and on Bougainvil