The Slave River is a Canadian river that flows from Lake Athabasca in northeastern Alberta and empties into Great Slave Lake. The river is 434 km in length.

The Peace and Athabasca Rivers drain into the Slave River. Water from this river reaches the Arctic Ocean through the Mackenzie River.

This river's name is thought to come from a Cree name which meant "slave" or "stranger". The Cree had displaced other native people from this region.