Ternberg is a municipality in the district of Steyr-Land, in the Austrian state of Upper Austria. It lies in the Traunviertel region of the country, within the Enns valley area of Upper Austria.
The municipality is located in the foothills of the Upper Austrian Alps, near the confluence of the Trattenbach and the Enns rivers. The surrounding landscape is characterised by forested hills and river valleys typical of the Steyr-Land district.
Ternberg is one of the municipalities that make up the Steyr-Land district, which is centred on the city of Steyr. The area is served by the Ennstalbahn railway line, which connects the region to the wider Austrian rail network.