Cachisca Lake is a body of water in the Broadback River watershed in the Eeyou Istchee James Bay (municipality) area of the Nord-du-Québec, in the province of Quebec, in Canada.

This lake is part of the territory of Assinica Wildlife Sanctuary and Turgis Township.

The surface of Cachisca Lake is usually frozen from early November to mid-May, however, safe ice movement is generally from mid-November to mid-April.

Of Cree origin, this hydronym translates an abbreviated form of "Capacwachipsca", which could mean "lake rock in shallow water.

"[2] The toponym "Lac Cachisca" was formalized on December 5, 1968, by the Commission de toponymie du Québec, when it was created.