John A. Olthuis is one of the founding partners of OKT. His practice includes litigation, comprehensive and specific land rights, self-government, and impacts and benefits agreements. John was on the legal team of the Assembly of First Nations in negotiations with Canada and the provinces lending to the inclusion of "Section 35" in Canada’s repatriated Constitution in 1982. John was legal counsel to Chiefs of Ontario and table negotiator at the Aboriginal Government table for the Assembly of First Nations in the Charlottetown Accord Constitutional negotiations. He has appeared as counsel before numerous government boards and agencies. John has been selected annually by his peers for inclusion in directories of leading lawyers in the area of Aboriginal Law, including in The Best Lawyers in Canada 2014 and The Best Lawyers in America 2008. He has consistently been listed as Most Frequently Recommended by The Canadian Legal Lexpert Directory. In 2010, John was selected as Lawyer of the Year – Aboriginal law by The Best Lawyers in Canada. John was admitted to the Alberta Bar in 1965, the Ontario Bar in 1987 and the Newfoundland & Labrador Bar in 2015. John was awarded the Law Society Medal by the Law Society of Ontario in 2018 and was appointed Member of the Order of Canada in 2023.