| West Branch Little Dead Diamond River | |
| Pushpin Map: | New Hampshire#USA |
| Pushpin Map Size: | 250 px |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | New Hampshire |
| Subdivision Type3: | County |
| Subdivision Name3: | Coos |
| Subdivision Type4: | Townships |
| Subdivision Name4: | Clarksville Atkinson & Gilmanton Grant |
| Length: | 2.5miles |
| Source1: | Crystal Mountain |
| Source1 Location: | Clarksville |
| Source1 Coordinates: | 44.9675°N -71.2189°W |
| Source1 Elevation: | 2550feet |
| Mouth: | Little Dead Diamond River |
| Mouth Location: | Atkinson & Gilmanton Grant |
| Mouth Coordinates: | 44.9811°N -71.1778°W |
| Mouth Elevation: | 1790feet |
The West Branch of the Little Dead Diamond River is a 2.5adj=midNaNadj=mid[1] river in northern New Hampshire in the United States. It is a tributary of the Little Dead Diamond River, located in the Androscoggin River watershed of Maine and New Hampshire.
The river rises in the town of Clarksville on the eastern slopes of Crystal Mountain, a 7miles ridge. The river, never larger than a brook, flows northeast into the Atkinson and Gilmanton Academy Grant, where it joins the Little Dead Diamond River.