The 24th Battalion was an infantry battalion of the Australian Army. Originally raised in 1915 for service during World War I as part of the 1st Australian Imperial Force, it was attached to the 6th Brigade, 2nd Division and served during the Gallipoli campaign and in the trenches of the Western Front in France and Belgium. Following the end of the war the battalion was disbanded in 1919, however, in 1921 it was re-raised as a unit of the part-time Citizens Forces in Melbourne, Victoria. In 1927, when the part-time forces adopted territorial titles, the battalion adopted the designation of 24th Battalion (Kooyong Regiment). In 1939, the 24th Battalion was merged with the 39th Battalion, however, they were split up in 1941 and in 1943, after being allocated to the 15th Brigade, the 24th Battalion was deployed to New Guinea before later taking part in the Bougainville campaign. Following the end of the war, the battalion was disbanded in 1946.

The 23rd Battalion was an infantry battalion of the Australian Army. It was raised in 1915 as part of the Australian Imperial Force for service during World War I and formed part of the 6th Brigade, attached to the 2nd Division. After being formed in Australia, the battalion was sent to Egypt to complete its training, before being committed to the Gallipoli Campaign as reinforcements in September 1915. They remained on the peninsula until the evacuation of Allied troops in December, when they were withdrawn back to Egypt where they were reorganised before being transferred to the Western Front in March 1916. Over the course of the next two-and-a-half years, the 23rd took part in a number of significant battles in France and Belgium, before being disbanded in mid-1919 following the conclusion of hostilities. In 1921, the battalion was re-raised as a part-time unit within the Citizens Forces in the state of Victoria, but was amalgamated with the 21st Battalion in 1929 to form the 23rd/21st Battalion.