Waconichi Lake is a freshwater body of the Albanel, Mistassini and Waconichi Lakes Wildlife Sanctuary within the Eeyou Istchee Baie-James, in Jamésie, in the administrative region of Nord-du-Québec, in the province of Quebec, in Canada.

The hydrographic slope of Waconichi Lake is accessible on the southeast side by the forest road route 167, coming from the southwest, Chibougamau; and on the west side by a secondary road connecting to the south of the lake at route 167 and going north to the Assinica Wildlife Sanctuary.

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

Of Innu origin, the term Waconichi means "mountain of crumbled rocks".

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