James (Jim) William Saint George Walker was born on August 5, 1940, in Toronto, and grew up in Agincourt, Ontario. Walker received his Bachelor's degree in History from Trinity College at the University of Toronto (1962), his Master’s degree in History from the University of Waterloo (1967), and his Ph.D. in History from Dalhousie University (1973). In 1976, Walker published his Ph.D. dissertation under the title The Black Loyalists: the search for a promised land in Nova Scotia and Sierra Leone, 1783-1870 with Longman International Education, which he later republished with the University of Toronto Press in 1992 and 2017.

During his time as a student in the 1960s, Walker worked in a Gandhian ashram in India under the auspices of Canadian University Service Overseas (CUSO) and he participated in the local support group for the US civil rights movement (“Friends of SNCC”) in Toronto. During Canada’s Centennial, he was Youth and Education Director for the Centennial International Development Programme. While at Dalhousie, Walker co-founded and taught the "Transition Year Program" designed to prepare African-Canadian and First Nations students for university entrance.

James Walker joined the University of Waterloo as a History professor in 1971. At the University of Waterloo, he created the first university-level course in African-Canadian History offered in Canada and Canada's first Public History graduate program; served as Chair of the Department of History (1981-1986); and taught courses in general History and Race relations, courses focused on Black Canadian and African History, and courses on Social History and Public History. During his research, teaching, and public speaker career his talks, publications, and courses focused on the history of African-Canadians, Canadian and international human rights, Racism in Canada, Race relations in Canada, Immigration, the Holocaust, and civil society and public history.

While in Waterloo, Walker co-founded and was a long-time board member of the Global Community Centre of Kitchener-Waterloo and has served on the boards of several NGOs with an international focus (including CUSO, the WUSC local committee, and the board of the Shastri Indo-Canadian Institute). Between 2003 and 2004, the Social Science and Humanities Research Council appointed Walker the Bora Laskin National Fellow in Human Rights Research. In 2013, Walker was elected a Fellow of the Royal Society of Canada. And in 2016, he was invested as a Member of the Order of Canada.

In 2020, Walker retired from his professor role and remained as Distinguished Professor Emeritus of the University of Waterloo.

During his professional years, James Walker published numerous articles, book chapters, and books, including, among others:

• The Black Loyalists : The Search for a Promised Land in Nova Scotia and Sierra Leone, Longman and Dalhousie University Press, 1976 (1992, 2017).
• Racial discrimination in Canada: the Black experience, Canadian Historical Association, 1985.
• "Race," Rights and the Law in the Supreme Court of Canada: Historical Case Studies, The Osgoode Society and Wilfrid Laurier University Press, 1997.
• Critical Mass: The Emergence of Global Civil Society, Centre for International Governance Innovation and Wilfrid Laurier University Press, co-authored with Andrew Thompson, 2008.
• “A Black Day in Court: ‘Race’ and Judging in R v RDS” in The African-Canadian Legal Odyssey, edited by Barrington Walker, Osgoode Society for Canadian Legal History and University of Toronto Press, 2012.
• Burnley "Rocky" Jones : revolutionary : an autobiography, Fernwood Publishing, 2016.