| Trinidad River | |
| Source1 Location: | Sierra Madre de Oaxaca |
| Mouth Location: | San Juan River |
| Subdivision Type1: | Country |
| Subdivision Name1: | Mexico |
| Subdivision Type2: | State |
| Subdivision Name2: | Oaxaca |
The Trinidad River (Mexico) is a river of Oaxaca state in Mexico.
It originates in the Sierra de Villa Alta sub-range of the Sierra Madre de Oaxaca and flows northeastwards onto the Gulf Coastal Plain, where it joins the Lalana River to form the San Juan River. The San Juan is a tributary of the Papaloapan River, which empties into the Gulf of Mexico.