[1] The organization's roots predate European contact in the 16th century, in the Council of Three Fires.
[citation needed] The Union of Ontario Indians was incorporated in 1949 to serve as a political advocate and secretariat for the Anishinabek First Nations.
[2] In 2017, the Council changed its identification using the name "Union of Ontario Indians" only for legally-binding agreements but for all other purposes referred to themselves as Anishinabek Nation.
In 2018, an organizational restructuring introduced four regional deputy grand council chiefs.
Their logo, a stylized thunderbird, was created in the 1970s by Nick Deleary.