The Union of Ontario Indians is a First Nations political organization representing 39 member First Nations in the Canadian province of Ontario. The organization's roots predate European contact, and it was incorporated in 1949 to serve as a political advocate and secretariat for the Anishinabek Nation. The head office for the Union of Ontario Indians is located at Nipissing First Nation near North Bay, Ontario.
The Union of Ontario Indians is guided by a Leadership Council, consisting of a Grand Council Chief, a Deputy Grand Council Chief and grand chief, council members and elders representing four geographic regions: Northern Superior, Lake Huron, Southeast and Southwest.
There are currently about 60,000 citizens of the Anishinabek Nation member communities, accounting for about one-third of the total First Nation population in the province of Ontario.