The 30th Battalion was an infantry battalion of the Australian Army. It was originally formed in 1915 during the First World War and saw service on the Western Front before being disbanded in 1919. It was re-raised in 1921 but was later amalgamated with the 51st Battalion in 1930. In 1935 the two battalions were delinked and the 30th re-raised in its own right. During the Second World War it undertook garrison duties in Australia before undertaking active service in New Guinea in 1944–45. After the war, it was disbanded in early 1946. In 1948 the battalion was re-raised again and remained on the order of battle until 1960 when it was absorbed into the Royal New South Wales Regiment.