| Big 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: | Counties |
| Subdivision Name3: | Strafford, Belknap |
| Subdivision Type4: | Towns |
| Subdivision Name4: | New Durham, Strafford, Barnstead |
| Length: | 14.9miles |
| Source1: | unnamed pond |
| Source1 Location: | New Durham |
| Source1 Coordinates: | 43.3572°N -71.1578°W |
| Source1 Elevation: | 831feet |
| Mouth: | Suncook River |
| Mouth Location: | Barnstead |
| Mouth Coordinates: | 43.3364°N -71.2608°W |
| Mouth Elevation: | 490feet |
| Tributaries Left: | Little River |
The Big River is a 14.9adj=midNaNadj=mid[1] river located in central New Hampshire in the United States. It is a tributary of the Suncook River, part of the Merrimack River (and therefore Gulf of Maine) watershed.
Headwaters of the Big River rise on high ground in the southern corners of Alton and New Durham, New Hampshire. The river flows southeast into Strafford, then, running up against the Blue Hills Range, the river reverses course, turning west into Barnstead, where it meets the Suncook River in the village of Center Barnstead.