The 9th Battalion was raised as part of the all-volunteer First Australian Imperial Force for service in the First World War. Completely recruited from Queensland, along with 10th, 11th and 12th Battalions, the 9th Battalion formed the 3rd Brigade, of the 1st Division. The battalion was formed shortly after the war broke out and after a short period of training, it departed Brisbane on 24 September 1914 on board the transport SS "Omrah" (HMAT A5). While en route members of the battalion provided a guard for the 44 survivors of the . Initially, they had been bound for the United Kingdom, but concerns about overcrowding in the training camps there meant that the decision was made to land the 1st Division in Egypt, where it would complete its training before being transported to the Western Front.