The Ongarue River is a river of the Waikato and Manawatu-Wanganui Regions of New Zealand's North Island. A major tributary of the Whanganui River, it flows west then south from its sources in the Hauhungaroa Range northwest of Lake Taupo, passing through the town of Taumarunui before reaching the Whanganui River.
Tributaries of the Ongarue include the Maramataha River and the Taringamotu River.
"Place Name Detail: Ongarue River". New Zealand Geographic Placenames Database. Land Information New Zealand. Retrieved 12 July 2009.
Coordinates: 38°53′S 175°15′E / 38.883°S 175.250°E