| Zomandao River | |
| Map: | Mangoki drainage.png |
| Subdivision Type1: | Country |
| Subdivision Name1: | Madagascar |
| Subdivision Type3: | Region |
| Subdivision Name3: | Haute Matsiatra, Ihorombe |
| Subdivision Type5: | Cities |
| Subdivision Name5: | Fenoarivo Atsinanana, Ihosy |
| Length: | 283km (176miles) |
| Source1 Location: | Andringitra Massif, Pic Boby, Haute Matsiatra |
| Source1 Elevation: | 2600m (8,500feet) |
| Mouth: | Mangoky river |
| Mouth Location: | between Bekininy and Sakananjy, Ihorombe |
| Mouth Coordinates: | -21.5958°N 45.4122°W |
| Mouth Elevation: | 193m (633feet) |
| Basin Size: | 10300km2 |
| Tributaries Left: | Sohanambo River, Ihosy |
The Zomandao River is a 283-km-long river in the regions of Haute Matsiatra and Ihorombe in central-southern Madagascar. It begins in the Andringitra Massif at Boby Peak,[1] the second highest peak of Madagascar, and flows across the Zomandao Plain. It is one of the main tributaries of the Mangoky River. It has some waterfalls, including the Riandahy Falls and Rianbavy Falls.
A main attribute to the Zomandao River is the Ihosy River.