The 2/1st Pioneer Battalion was a pioneer battalion of the Australian Army during World War II. Raised in early 1940, the battalion served throughout the war, seeing action in North Africa, particularly around Tobruk in 1941, before being brought back to Australia in 1942. It later took part in the fighting against the Japanese in New Guinea in 1942–43, and then in Borneo in 1945. It was disbanded in early 1946. The battalion undertook both infantry and engineer tasks.

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