| Boulder River | |
| Pushpin Map: | New Zealand#New Zealand South Island |
| Pushpin Map Size: | 270px |
| Pushpin Map Caption: | Mouth of the Boulder River |
| Source1 Location: | Boulder Lake |
| Source1 Coordinates: | -40.8893°N 172.575°W |
| Mouth Location: | Aorere River |
| Mouth Coordinates: | -40.8024°N 172.5488°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | New Zealand |
| Progression: | Boulder River → Aorere River → Ruataniwha Inlet → Golden Bay / Mohua → Tasman Sea |
| Tributaries Left: | Amphitheatre Creek |
| Tributaries Right: | Parson Creek |
The Boulder River is a small river in the north of the South Island of New Zealand.
The headwaters are at the Kahurangi National Park's small Boulder Lake. The river flows north for 10km (10miles) before draining into the Aorere River.