Lake Magpie is in the unorganized territory of Lac-Jérôme in the Minganie Regional County Municipality.

[3] The lake is named for the Canada jay (Perisoreus canadensis), a bird closely related to the magpie.

[4] The West Magpie River flows into the lake 50 kilometres (31 mi) above the south end.

[7] The lake and surrounding area have been protected against logging, mining or hydroelectric projects since 19 June 2003, with plans to make it a biodiversity reserve.

The Pourvoirie du Lac Magpie provides non-exclusive outfitting services from a camp at the north end of the lake.