The Whitesand River is a river in the Unorganized Part of Thunder Bay District in Northwestern Ontario, Canada, part of the Hewitson River system.
The river begins at North Whitesand Lake at an elevation of . The lake travels west, then turns south near the site of a mine. The Whitesand River then travels downstream via a series of lakes, including Cleaver Lake, Zenith Lake, Demijohn Lake, Gumboot Lake, Longcanoe Lake and Hornblende Lake. It then takes in its left tributary Ross Creek at Lyne Lake at at an elevation of , and reaches its mouth at Whitesand Lake at an elevation of just north of Ontario Highway 17. The mouth is about east northeast of the community of Rossport and northwest of the community of Schreiber. The Whitesand River's waters flow from Whitesand Lake via the Hewitson River over the Rainbow Falls into Lake Superior.
An access road to the mine runs from Highway 17 along the river. A campground of Rainbow Falls Provincial Park is on the south side of Whitesand Lake opposite the mouth of the Whitesand River.