Lake Poncheville is a freshwater body in of Eeyou Istchee Baie-James (municipality), in the administrative region of Nord-du-Québec, in the province of Quebec, in Canada.

In addition, the Quénonisca Lake (located to the north) of a length of 52.1 kilometres (32.4 mi) offers another navigable body of water that connects to the Broadback River.

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

This mouth is located at the bottom of a bay, at: The main hydrographic slopes near Poncheville Lake are: A cartographic document of 1911 refers to this body of water under the name of "Lady Beatrix Lake", name of one of the two daughters of the Marquis de Lansdowne, Governor General of Canada from 1883 to 1888.

This place name will remain in the documents until 1963, while a new toponym was officialized that evokes the Canon Charles Thellier of Poncheville (1875-1956).