| Mason River | |
| Source1 Location: | Amuri Range |
| Mouth Location: | Waiau River |
| Subdivision Type1: | Country |
| Subdivision Name1: | New Zealand |
| Length: | 36km (22miles) |
The Mason River is a river of the north Canterbury region of New Zealand's South Island. It flows south from the Amuri Range, at the foot of the Mason Hills before turning southwest to reach the Waiau River just to the west of the township of Waiau.