John Whitton Haslem was born in Melbourne, Victoria and educated at Brighton Grammar School and Melbourne University where he attained an LLB and B.Com. His early career was as a solicitor in Melbourne before moving to Canberra in 1965 to join the Federal Department of Trade and Industry. He returned to legal practice in 1970 with a leading Canberra law firm, Macphillamy Cummins & Gibson, where he became a Partner. In 1975 he stood for pre-selection for the Federal Electorate of Canberra for the Liberal Party.