Conlon's parents were Arthur George Conlon, tram conductor, and Esther Mary, née Hayes. He was born at East Sydney and was educated at Fort Street Boys' High School and the University of Sydney, graduating BA in 1931. He studied philosophy under the realist Professor John Anderson. He began to study medicine in 1932 at the University of Sydney but interrupted the course to work as a law clerk and get married. The following year he returned to his medical studies and represented undergraduates on the university's senate in 1939–43. He also served as a manpower and education officer in 1940–41. In April 1942, through a friend, the army's wartime adjutant-general Victor Stantke, Conlon became Major Conlon and head of the research section at the Australian Army’s headquarters, then at Victoria Barracks in St Kilda Road, Melbourne. He had previously been chairman of the Prime Minister’s Committee on National Morale. Described as "a clever man and a brilliant talker", "Svengali-like" and notorious, Conlon created the mysterious DORCA in part as a haven for artists and intellectuals to avoid repeating the slaughter of the best minds of a generation that had impoverished Australian culture in the First World War. Conlon was influenced by his first philosophy teacher, John Anderson, and by James Burnham's The Managerial Revolution, a book extolling the virtues of a bureaucratic meritocracy. Conlon was a charismatic figure, and had many friends in high places including H. V. Evatt and Herbert "Nugget" Coombs. He cultivated many contacts including Prime MinisterJohn Curtin and General Thomas Blamey. In 1944, with Roy Wright, General Blamey and Howard Florey, Conlon developed the proposal for founding the John Curtin School of Medical Research. Conlon became principal of ASOPA after John Kerr's resignation in 1948. He resumed his medical degree at the University of Sydney in 1950 and graduated MB, BS in 1951, "with difficulty, and despite opposition from members of the faculty". He subsequently practised as a psychiatrist from his home in North Sydney until his death at the age of 53.
