Sir Douglas graduated in 1920.
Sir Douglas was an all-rounder, a law firm partner, a volunteer of the Defence Corps and a board member, chairman and director of countless companies. He was also heavily involved in the Catholic Church as a member of the Business Advisory Board of the Catholic Leader.
Sir Douglas passed away in 1984. Following his passing, the canine pavilion at the Brisbane showgrounds was named in his honour and the Sir Douglas Wadley Handicap is a major event in the Queensland horse racing calendar.