Dr. William Lyon MacKenzie King III

Pre-deceased by the love of his life and wife of 61 years, Joan. Cherished brother of Kathy Mezei (Leslie). Loving father of Bill (Leslie) and Nelson (Marie). Deeply beloved grandfather (Poppa) of Mackenzie, Tobias, Brianna, Graydon, Jamieson, Macallan and Cassandra. Bill/Mac/Kenzie was born in Rochester, Minnesota while his father was training at the Mayo Clinic. Grand-nephew of William Lyon Mackenzie King, Prime Minister of Canada for over 21 years. His father, William Lyon Mackenzie King II, graduated from the University of Toronto Faculty of Medicine in 1937 and served as a surgeon in the Canadian Navy before being tragically killed during the Second World War. His mother, Margery King (née Rean), became the matriarch of the King family, raising Bill and Kathy while returning to the University of Western Ontario and earning her PhD as a single mother. Bill was raised in Toronto, attending UTS high school and later U of T medical school where he graduated in 1965. He continued his training and became a Fellow of the Royal College of Surgeons in 1970. During those demanding years, he and Joan somehow also managed to raise two young sons, Billy and Nelson. After completing his surgical training in Toronto, the family travelled to England for a year of specialized training in vascular surgery, followed by six months travelling through Europe in a van with two young children, aged five and six; an early sign of the adventures that would define their family life. After returning to Canada, Bill started his career at North York General Hospital where he worked for over 30 years. Away from work, Bill's passion was the outdoors. Beginning with a canoe trip to Temagami with his boys in 1974 (thanks Alex Furness and the Howells), he became a lifelong canoe tripper, flying all over Canada and even naming a river in the Northwest Territories. Bill was a long time contributing member of the Wilderness Canoe Association (WCA), serving in the past as president of the organization and for many years co-ordinating there presentation at the Toronto Sportsman Show. Travel was always a shared family passion and trips to every corner of the globe are a tribute. Closer to home, a condo in Fernie, B.C. was an incredible family retreat for many years, particularly for the grandchildren for whom trips with Nana and Poppa were always a highlight. Poppa also had musical talents that brought the family together. He played the piano entirely by ear, filling their home on Hi Mount with Christmas carols over the holidays, and familiar tunes during countless birthday celebrations, creating memories cherished by all family members. Later in life, dedicated work at the College of Physicians and Surgeons of Ontario brought tremendous satisfaction and reflected his enduring commitment to both the medical profession and the public. An active member of the Rotary Club of Willowdale, he formed lasting friendships and found great purpose in giving back to his community. In later years, he walked alongside his bride through her courageous battle and journey with breast cancer, which brought many tears but no regrets. Although elderly, in the end it was an accidental fall at home and not old age that led to Poppa’s passing. Many thanks and admiration to the team at Sunnybrook who were, to a person, exemplary. Special thanks to Dr. Haas. Barb, you are a caring and incredible person and your care and compassion will not be forgotten. Kenzie will be remembered for his charm, kindness, care for others, and the ever-present glint in his eye. He will be deeply missed and fondly remembered by all who had the privilege of sharing in his journey.

A celebration of Life for William will be held at Kane-Jerrett Funeral Homes - Thornhill (8088 Yonge St) on Sunday, February 8, 2026 from 1:00pm - 4:00pm. Words will be shared at 2:00pm