Young River () is in the Otago region of the South Island of New Zealand. It lies within the Mount Aspiring National Park and feeds into the Makarora River upriver from Makarora.
The ultimate source of the Young River is at the head of Young River North Branch on the eastern slopes of Mount Doris on the main divide of the Southern Alps / KÃÂ Tiritiri o te Moana. The river flow eastwards from it source. There is a landslide dam and long lake downstream, that formed in 2007. At the lake the river bends to the right and flows southwards for . The Gillespie Pass Circuit tramping track crosses the river using the Young Fork Bridge.
At Young Fork approximately downstream from the source of the north branch the Young River South Branch merges from the right. The river continues in flowing eastwards for until it ultimately merges with the Makarora River north of the village of Makarora
At 4:40 a.m. on August 29, 2007, a debris avalanche occurred blocking the Young River North Branch. Approximately of material fell in to the river valley from above forming a high landslide dam. A new lake began forming behind the dam. The lake eventually overtopped the dam on 5 October 2007. When fill, the lake is long and wide and has a volume of .