Zasap is a settlement located in eastern Slovenia within the Municipality of Brežice. It is situated north of Cerklje ob Krki and is part of the traditional region of Lower Carniola. Administratively, it is currently included in the Lower Sava Statistical Region.
The area is notable for its proximity to the Cerklje ob Krki Air Base, as the western portion of the base's runway lies within the territory of Zasap.