The Nechako River (Dakelh: ᘅᐪᙠᗶᑋ) /nəˈtʃækoʊ/ arises on the Nechako Plateau east of the Kitimat Ranges of the Coast Mountains of British Columbia, Canada, and flows north toward Fort Fraser, then east to Prince George where it enters the Fraser River.

"Nechako" is an anglicization of netʃa koh, its name in the indigenous Carrier language which means "big river".

The Nechako is one of the main tributaries of the Fraser River, although half[5] of its flow was diverted through the Coast Mountains to the Kemano generating station at sea level on the Gardner Canal, 858 metres (2,815 ft) below the reservoir's intakes, which supplies power to the aluminum smelter at nearby Kitimat.

The damming of the Nechako in 1952 and the consequent massive reduction in flow has been the source of considerable political controversy.

The increase in water temperature caused by the reduction in flow has been an ongoing problem for the salmon run on the Fraser and Stuart Rivers as well as the Nechako.