During the course of Bill Cossey's 38-year career in the public service he held a number of senior positions within State Government departments including chief executive officer of the State Services Department, the Office of Business and Regional Development, the Office of the Government Management Board, the Department of Education, Training and Employment and the Attorney-General's Department.
Prior to his retirement in 2004, he was chief executive of the State Courts Administration Authority, a position he held for five years, and prior to serving in that role he was deputy chief executive of the Department of Industry and Trade and chief executive officer of the Adelaide Festival Centre Trust.
Having begun his professional career with a Bachelor of Science with majors in mathematics and mathematical statistics from the University of Adelaide, Mr Cossey continues to serve on the governing councils of the University of South Australia, the Adelaide Benevolent Society and the Eastern Waste Management Authority. He also chairs the boards of the Energy and Water Ombudsman's Office, Tennis SA, the Don Dunstan Foundation and People's Choice Credit Union.
In June 2004, Mr Cossey was made a Member of the Order of Australia for services to government and to the community.