| North Fork Trinity River | |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | California |
| Subdivision Type5: | City |
| Subdivision Name5: | Helena |
| Length: | 25miles |
| Discharge1 Location: | Helena, CA |
| Discharge1 Min: | 7.5cuft/s |
| Discharge1 Avg: | 431cuft/s |
| Discharge1 Max: | 35800cuft/s |
| Source1: | Rays Peak and Chikoot Pass |
| Source1 Location: | Trinity National Forest |
| Source1 Coordinates: | 41.0733°N -123.165°W |
| Source1 Elevation: | 5700feet |
| Mouth: | Trinity River |
| Mouth Location: | Helena |
| Mouth Coordinates: | 40.7706°N -123.1275°W |
| Mouth Elevation: | 1358feet |
| Basin Size: | 151sqmi |
| Tributaries Left: | Grizzly Creek, East Fork North Fork Trinity River |
The North Fork Trinity River is a tributary of the Trinity River in the U.S. state of California. It flows south through the Klamath Mountains for about 25miles, emptying into the Trinity at Helena, about 5miles northeast of Junction City. The river drains an area of 151mi2. Important tributaries include the East Fork North Fork Trinity River and Grizzly Creek.