The Waihou River is located in the northern North Island of New Zealand. Its former name, Thames River, was bestowed by Captain James Cook in November 1769, when he explored 14 mi (23 km) of the river from the mouth. An older Māori name was "Wai Kahou Rounga". A 1947 Geographic Board enquiry ruled that the official name would be Waihou.

Putāruru is a small town in the South Waikato District and the Waikato region of New Zealand's North Island. It lies on the western side of the Mamaku Ranges and in the upper basin of the Waihou River. It is on the Oraka Stream 65 kilometres south-east of Hamilton. State Highway 1 and the Kinleith Branch railway run through the town.