Wiseman was born in Niagara Falls, Ontario, and raised in Burlington by his mother, a physiotherapist, and his father, a plumber and pipe fitter who headed a division of a construction company.

[3][4] Early in his career, Wiseman was an officer with Harrowston, a publicly traded Canadian merchant bank and a lawyer with Sullivan & Cromwell, practicing in New York and Paris.

[5] Then, Wiseman was responsible for the private equity fund and co-investment program at the Ontario Teachers' Pension Plan.

[11][12] Wiseman is the Co-Founder and former Chairman of FCLTGlobal (formerly Focusing Capital on the Long Term), an organization that encourages longer-term approaches in business and investing, which was set up by BlackRock, CPPIB, Dow, McKinsey & Company and Tata in 2016.

[2] For more than twenty years, Wiseman was in a common-law relationship with Marcia Moffat, whom he met on his first day at University of Toronto.