William Tetley was born in Montreal on February 10, 1927, the son of Francis William Tetley and Gertrude Aubrey. He attended the Town of Mount Royal High School, the Royal Canadian Naval College, McGill University, and the Université de Laval. Tetley served in the navy and in the Reserve from 1945-1951. He was admitted to the Quebec Bar in June of 1952. He practiced law in Montreal until 1968 and represented Canada at the Congress on International Law in Athens (1961), Stockholm (1963), and New York (1966). He entered municipal politics and was elected as a councillor for the Town of Mount Royal in 1965, and elected to the Legislative Assembly of Quebec in a 1968 by-election as the Liberal Party representative for Notre-Dame-de-Grâce. He was appointed Minister of Revenue in 1970 and became Minister of Financial Institutions, Companies, Cooperatives and Consumer Protection later than year. During his second mandate in this position, Tetley led the adoption of Quebec's first consumer protection act in 1975. Before his retirement from politics, he served as the Minister of Public Works and Supply from July 1975 to November 1976. He was appointed a professor at McGill's Faculty of Law in 1976 and was an associate professor of maritime law at Tulane University in New Orleans, Louisiana, from 1984 to 1998. He authored numerous books and articles on maritime law. He was named to the Order of Canada in 1995. Tetley married Rosslyn on Mary 14, 1955, with whom he had four children. He died on July 1, 2014, in Montreal at the age of 87.