The Lake McSweeney is a freshwater body located in the Center-East part of Gouin Reservoir, in the territory of the town of La Tuque, in the administrative region of the Mauricie, in the province of Quebec, in Canada.

This lake in the middle of the Center-East part of the Gouin reservoir straddles the townships of McSweeney, Magnan, Marmette and Brochu.

The hydrographic slope of Lake McSweeney is served indirectly on the north side by route 212 connecting the village of Obedjiwan to the east shore of the Gouin Reservoir; this road provides access to Toussaint Lake and to the various bays on the northeast shore of the Gouin Reservoir.

A few secondary forest roads have been built on the North-North shore of the Gouin Reservoir for logging and recreational activities.

Before the construction of La Loutre Dam was completed in 1916, thus creating Gouin Reservoir, lake McSweeney had a smaller dimension.