The 2/3rd Pioneer Battalion was a pioneer battalion of the Australian Army, which served during World War II. Formed in 1940, the battalion served in the Middle East where it fought in Syria and Palestine before taking part in the fighting around El Alamein. In 1943, the battalion returned to Australia and subsequently took part in the fighting against the Japanese in New Guinea in 1943–1944. Their final campaign came in mid-1945, when they took part in the Battle of Tarakan during the Borneo campaign. The battalion was disbanded in early 1946.

A pioneer is a soldier employed to perform engineering and construction tasks. The term is in principle similar to sapper or combat engineer.