The Municipality of Baie-James is in northern Quebec, Canada, to the east of James Bay. It covers 297,329.66 square kilometers of land, making it the largest incorporated municipality in Canada — only eight unorganized territories are larger. Its territory almost entirely (about 98%) covers the administrative region of Jamésie, although it contains less than five percent of the population. Essentially, it is the remainder of the Jamésie Territory's land after all of the major population centres have been removed.
The hydroelectric power plants of the La Grande Complex are all located within the municipal boundaries of Baie-James, making the municipality strategically important to Quebec's energy policy. Other important economic sectors are mining, softwood logging, forestry, and tourism.