Wunnumin Lake First Nation, located in northwestern Ontario, Canada, is an Oji-Cree First Nation band government. The community resides on the shores of Wunnummin Lake, approximately 360 kilometres (220 mi) northeast of Sioux Lookout. The First Nation is composed of two reserves: the primary reserve, Wunnumin 1, and the nearby Wunnumin 2. As of January 2007, the registered population of the community was 565.
Access to Wunnumin Lake First Nation is primarily through air transportation, with flights landing at the Wunnumin Lake Airport. However, during the winter season, the community can also be reached via the White Highway, a network of winter roads.
The Oji-Cree name for Wunnumin Lake is Wanaman-zaaga'igan, which translates to "Vermillion Lake". This name is a reference to the vermillion-coloured clay found around the lake. According to local legend, the Crane manidoo, Wiisagejaak, hunted for food in this area. He found a "Big Beaver" living on the Pipestone River and chased it and its baby to this area. Upon catching up with the beavers, Wiisagejaak killed the baby beaver and left it in the foliage. The blood from the baby beaver's wound seeped into the ground, staining the clay to its distinctive vermillion colour.
The residents of Wunnumin Lake originally hailed from Big Beaver House, Ontario. After a large forest fire, the community at Big Beaver House relocated to two separate locations, one of which was Wunnumin Lake. During 1929–1930, the leaders of Wunnumin Lake First Nation were summoned to Big Trout Lake to participate in the signing of the adhesion to Treaty 9. The community achieved their Reserve status on March 2, 1976, marking a significant milestone in their history.