The Lac des Îles (in English: lake of islands), also called Lac Grande Coudée is a lake located near the village of Saint-Hilaire-de-Dorset, in Beauce-Sartigan Regional County Municipality (MRC), in the administrative region of Chaudière-Appalaches, in Quebec, in Canada.

Its area is approximately 2 square kilometres (0.77 sq mi), its altitude of 420 metres (1,380 ft).

The discharge from the lake joins the Rivière de la Grande Coudée, near Saint-Martin.

[1] Camping, fishing, kayaking and various outdoor activities are accessible near the lake and its surrounding area in a natural environment.

The toponym "Lac des Îles" was made official on January 31, 1980, at the Commission de toponymie du Québec.