The Lac de l'Orignal (in English: Moose Lake) is a lake located on the territory of the village of Nantes, near Lac-Mégantic in Estrie, in Quebec, in Canada.

Its maximum approximate depth is 5.5 metres (18 ft), its width is 300 metres (980 ft) and its length is 650 metres (2,130 ft).

The Lake is accessible by rang 10 which joins the "Chemin du Lac de L'Orignal" and runs along part of the lake.

Most of the land is private and inhabited.

The lake is adjacent to a marsh to the west, which is crossed by the Glen River.