William George "Bill" Hayden AC (born 23 January 1933) is an Australian politician who was the 21st Governor-General of Australia from 1989 to 1996. He was previously the Leader of the Labor Party and Leader of the Opposition from 1977 to 1983, and served as Minister for Foreign Affairs and Trade under Prime Minister Bob Hawke from 1983 to 1988. Earlier he had briefly been the Treasurer of Australia under Gough Whitlam in 1975.