The Red Deer River begins at the north end of Nut Lake[2] near Highway 349 and west of Porcupine Hills in east central Saskatchewan.

[5] From the forests and hills, it continues eastward into Manitoba where 13 kilometres (8.1 mi) past the border, it opens up into Red Deer Lake.

Near the point where it empties into Dawson Bay, it crosses Highway 10, which is part of the Northern Woods and Water Route.

In 1757, a Hudson's Bay Company fur trading post was established alongside the Red Deer River near the village of Erwood.

Red Deer River tributaries from upstream to downstream, not including ones flowing into either Nut or Red Deer Lakes: Several types of fish live in the river, including freshwater drum, brown bullhead, common carp, goldeye, northern pike, and brown trout.