Katabasis or catabasis (Ancient Greek: κατάβασις, from κατὰ "down" and βαίνω "go") is a descent of some type, such as moving downhill, moving to a lower realm of existence, a military retreat, or a regression of some type.
- Katabasis, a trip to the underworld or the land of the dead
- Katabatic wind, cold winds that come from glacial mountains downward
- Katabasia, a type of hymn in the Eastern Orthodox Church and Eastern Catholic Churches which follow the Byzantine Rite