In 1921, the battalion was reformed as a militia unit known as the 17th Battalion (North Sydney Regiment), before being disbanded in 1944. The battalion was reformed in 1948 as an amalgamated unit known as the 17th/18th Battalion (The North Shore Regiment), before being reduced to a company-sized element in the 2nd Battalion, Royal New South Wales Regiment in 1960. In 1965, the battalion was reformed again as the 17th Battalion, Royal New South Wales Regiment, before being amalgamated to form the 2nd/17th Battalion, Royal New South Wales Regiment in 1987.