| Klosterwasser/Klóšterska woda | |
| Mouth Coordinates: | 51.3529°N 14.2451°W |
| Subdivision Type1: | Country |
| Subdivision Type3: | Region |
| Length: | ±25km (16miles) |
| Discharge1 Avg: | 4.91m3/s |
| Basin Size: | 107km2 |
Klosterwasser (Upper Sorbian: Klóšterska woda, pronounced as /hsb/) is a river of Saxony, Germany. It is a right tributary of the Black Elster, which it joins near Wittichenau. The source of the Klosterwasser/Klóšterska woda is located in Burkau/Porchow, Germany, in the Lusatian Highlands (Lausitzer Bergland) near the Czech border.