Oberaich is a former municipality in the district of Bruck-Mürzzuschlag, in the Austrian state of Styria. It lies in the eastern part of the country, within the Mur valley area of Upper Styria, near the town of Bruck an der Mur.
Since the 2015 Styria municipal structural reform, Oberaich has been part of the municipality of Bruck an der Mur. Before that reorganization, it existed as an independent municipality within the same district.