The 5th Machine Gun Battalion was an infantry support unit of the Australian Army. Originally formed in March 1918 for service during World War I as part of the all volunteer Australian Imperial Force, it was one of five such units raised as part of the AIF during the war. The battalion consisted of four machine gun companies, which had previously existed as independent companies assigned mainly at brigade level. The battalion took part in the final stages of the war, seeing action during the Allied defensive operations during the German spring offensive and then the Allied Hundred Days Offensive, which finally brought an end to the war. The battalion was disbanded in mid-1919 during the demobilisation of the AIF following the conclusion of hostilities. During World War II, the battalion w