Brežice is a town located in eastern Slovenia within the Lower Sava Valley, situated near the Croatian border. It serves as the administrative seat of the Municipality of Brežice and is positioned in the center of the Brežice Plain, which forms part of the larger Krka Flat.
Historically, the area surrounding the town was divided between the regions of Lower Styria and Lower Carniola. Today, the entire municipality is officially included in the Lower Sava Statistical Region.