The Waiwhakaiho River is a river of the Taranaki Region of New Zealand's North Island. One of many rivers and streams radiating from the slopes of Taranaki/Mount Egmont, it flows initially northeast before veering northwest to reach the Tasman Sea close to the New Plymouth suburb of Fitzroy. Near the sea, it is crossed by the coastal walkway, connecting New Plymouth with Bell Block via the Te Rewa Rewa Bridge. The river is also bridged by SH3 and the Marton–New Plymouth railway line.