Theodore Fontaine was a member of the Sagkeeng First Nation in Manitoba. He attended the Fort Alexander Indian Residential School from 1948 until 1958, and the Assiniboia Indian Residential School from 1958 to 1960. He was chief of the Sagkeeng First Nation from 1979 to 1981, and has worked for the federal Secretary of State Department; for the Northwest Territories Region of Indian and Northern Affairs Canada; as executive director of the Assembly of Manitoba Chiefs; and as Strategic Advisor to the Chiefs on Indian residential school issues. He was instrumental in negotiating and finalizing the national employment equity settlement with national corporations and the Canadian Human Rights Commission. He chaired the Indigenous Leadership Development Institute, a national leadership training institute based in Winnipeg. In April 2010 he was appointed to the Board of Governors of The Manitoba Museum. He died in May 2021.