Sevnica is a town located in central Slovenia on the left bank of the Sava River. It serves as the administrative seat of the Municipality of Sevnica and stands as one of the three major settlements within the Lower Sava Valley.
The town's layout consists of two distinct areas: an old town situated beneath Sevnica Castle on top of Castle Hill, and a newer section extending along the plain among the hills. This new core is positioned at the confluence of the Sevnična and Sava rivers.