J.D. Mitchell grew up and completed his schooling in Dartmouth, Nova Scotia. He then enlisted in the Forces where he served with distinction as an officer with the Canadian-American First Special Service Force during World War II, seeing action in Italy where he was decorated for gallantry, receiving both the American Silver Star and the Purple Heart. Following the war, he obtained his degree in architecture. He was a partner in one of Atlantic Canada's larger architectural firms, Fowler, Bauld and Mitchell, which specialized in the design of hospitals, universities, and municipal buildings such as the Rebecca Cohn Auditorium and the Halifax Metro Centre.

During his lifetime, he was active in numerous other businesses, volunteer and charitable organizations. He was recognized for his many years of service with St. John Ambulance when he was invested as a Commander in the Order of St. John on his 75th birthday.He was an enthusiastic golfer, playing the game in his own unique style. It is only fitting that he be remembered with the annual J.D. Mitchell Kilted Golf Classic-tournament proceeds in support of the Dartmouth General Hospital.