The Winisk River is a river in northern Ontario, Canada, that starts at Wunnummin Lake and flows east to Winisk Lake. From there it continues in a mostly northerly direction to Hudson Bay. The Winisk River is 475 kilometres (295 mi) long and has a drainage basin of 67,300 square kilometres (26,000 sq mi). The name is from Cree origin meaning "groundhog".

The river is remote and not accessible by road. Only a few isolated communities are along the river: Wunnumin Lake First Nation (on same lake), Webequie (on Winisk Lake) and Peawanuck, about 30 kilometres (19 mi) from its end. It is characterized by strong currents and whitewater while flowing off the Canadian Shield into the Hudson Bay lowlands. Here the river becomes broad.

• Pipestone River
• Asheweig River
• Shamattawa River

For most of the length of the Winisk River and its banks, from Winisk Lake to the Polar Bear Provincial Park, has been designated a provincial waterway park.

It is a non-operating park, meaning no fees are charged and no visitor facilities or services are present. Visitors must be experienced in travelling through isolated wilderness and skilled in handling whitewater.

• List of rivers of Ontario

Media related to Winisk River at Wikimedia Commons

• Ontario Parks - Winisk River Official Website