At a young age he acted as Band Manager in Eastmain, and then as Chief of Eastmain. He played a key role in the 1973 legal proceedings concerning hydro development in James Bay, which eventually lead to the decision of Justice Malouf in favor of the James Bay Crees. He subsequently was the Chief Cree Negotiator of the JBNQA in 1974 and 1975. He also took part in the negotiations leading to the 1984 Cree-Naskapi (of Quebec) Act, Canada's first local self-government legislation. He was the first Director-General of the Cree School Board and played an important role in setting it up.

Ted Moses was instrumental in winning consultative status for the GCC(EI) from the United Nations in 1987. In 1989, he was elected as the Rapporteur of the United Nations meeting on the Effects of Racism and Racial Discrimination on the Social and Economic Relations between Indigenous Peoples and States. He is the first aboriginal person to be so honored by the international community. He is recognized as a United Nations expert on aboriginal and human rights, having several of his speeches and articles published in international journals.

He is a founding member of the Indigenous Initiative for Peace, and has accompanied many peace missions in conflict zones in Chiapas and Columbia.

Ted Moses acted for many years as the Cree ambassador, and continues to play a vital role in the on-going work at the United Nations to obtain recognition in international law of the rights of the world's indigenous peoples.

In 1996, Ted Moses was awarded an honorary degree of Doctor of Laws by the University of Saskatchewan in honor of his international human rights work and his advocacy on behalf of aboriginal peoples.

In 2001, Ted Moses was named Man of the Year by the news magazine l'Actualité. In 2002, he became the recipient of the highest honor recognized by the government of Quebec as Officer of the Order of Quebec. In 2003, the largest newspaper in Quebec, La Presse, announced that he had been chosen by an impartial panel made up of representatives of Quebec universities as the Personality of the Year.

In 2005, he was again honored with a second degree of Doctor of Laws by Concordia University for his work in defending the Cree Nation and in promoting aboriginal and human rights in Canada and Quebec.