| Ulot River | |
| Pushpin Map: | Visayas#Philippines |
| Subdivision Type1: | Country |
| Subdivision Name1: | Philippines |
| Subdivision Type2: | Region |
| Subdivision Name2: | Eastern Visayas |
| Subdivision Type3: | Provinces |
| Length: | 90km (60miles) |
| Source1 Location: | San Jose de Buan |
| Mouth Location: | Can-avid |
| Mouth Coordinates: | 11.9951°N 125.454°W[1] |
The Ulot River is the longest river in Samar,[2] the third largest island in the Philippines. The river runs from San Jose de Buan in the Samar Province and discharges into the Philippine Sea. It has a length of approximately .