Hired in April 2013 as the Director of Legal Affairs for the Montreal Canadiens, John Sedgwick works closely with the vice president, hockey operations, and the general manager. In July 2017, Sedgwick was appointed the Vice President of Hockey Operations and in February 2022, he was named assistant general manager. John's responsibilities include player contract negotiations and salary arbitrations, daily salary cap management and strategic planning, and the administration of all matters related to the NHL-NHLPA collective bargaining agreement.

Prior to joining the Canadiens, John was a member of the National Hockey League Hockey Operations Department in Toronto, where he worked from 2006 to 2013. Before returning to his hometown of Toronto in 2006, John practiced corporate and commercial law at McInnes Cooper LLP, in Halifax Nova Scotia.

John holds a Bachelor of Arts (honours) in Political Science from Acadia University and an LL.B. from Dalhousie University. He was called to the Nova Scotia Barristers' Society in 2005 and to the Law Society of Upper Canada in 2007.