| Barn River | |
| Pushpin Map: | New Zealand#New Zealand South Island |
| Pushpin Map Size: | 270px |
| Pushpin Map Caption: | Mouth of the Barn River |
| Subdivision Type1: | Country |
| Subdivision Name1: | New Zealand |
| Subdivision Type2: | region |
| Subdivision Name2: | West Coast Region |
| Subdivision Type3: | District |
| Subdivision Name3: | Westland District |
| Length: | 6.8km (04.2miles) |
| Source1: | Hermitage Swamp |
| Mouth Coordinates: | -44.0494°N 168.3908°W |
| Mouth Elevation: | < 10m (30feet) |
The Barn River is a small river in a remote area of the Westland district of New Zealand. Only 6km (04miles) long, it acts as the primary drainage of the south half of the Hermitage Swamp near the mouth of the Cascade River.