Senftenberg is a town in the district of Krems-Land, in the Austrian state of Lower Austria. It lies in the Waldviertel region of the state, northwest of the city of Krems an der Donau.
The town is best known for the ruins of Senftenberg Castle, which stand on a rocky hill above the Krems river valley. The castle dates to the medieval period and was later expanded; it is now preserved as a ruin and is a local landmark.
Senftenberg is a small community whose economy and daily life are tied to the surrounding countryside and to nearby Krems. It is reached by road from Krems and the surrounding villages of the Krems valley.