Paul Emile Lucien Rousseau was born on December 20, 1929 in Fort Frances, Ontario to Lucien Rousseau and Laura Comeau. He received his primary and secondary education in Fort Frances.
Rousseau worked at a car dealership in Fort Frances before moving to Melville, Saskatchewan in 1958. He operated Melville Motors until 1960, when he moved to Regina. Rousseau operated Neil Motors (1960-1968) and Crestview Chrysler (1969-1977) in Regina and was active in the local community, serving as a member of the boards of the United Way, YWCA and Globe Theatre.
Rousseau's political career began in 1975, when he ran unsuccessfully in the Regina South constituency. Rousseau was first elected to the Saskatchewan Legislature in 1978 and served as a Progressive Conservative MLA for the Regina South constituency until 1986. In 1979, he ran unsuccessfully for the leadership of the Progressive Conservative Party.
Rousseau served in the Grant Devine Government as Minister of Industry and Commerce (1982-1983); Minister of Economic Development and Trade (1983) and Minister of Revenue and Financial Services (1983-1985). Rousseau was Minister Responsible for Crown Investments Corporation (1982-1983); Saskatchewan Government Insurance (1982-1985); Saskatchewan Economic Development Corporation (1982-1983); Saskatchewan Development Fund (1983-1985); Board of Revenue Commissioners (1983-1985); Public Service Superannuation Board (1983-1985) and Public Service Superannuation Plan (1983-1985).
Rousseau's cabinet appointments were discontinued on December 16, 1985 when Premier Devine shuffled his Cabinet and reduced the number of ministers. Rousseau resigned his seat in the Legislature in March, 1986 and Jack Klein (Progressive Conservative) became MLA for Regina South in November, 1986. On June 1, 1986, Rousseau was appointed Agent General for Saskatchewan in London, England and held the position until 1991, when he returned to Regina and retired from political life.
Rousseau died on October 8, 2001 in Regina.
Paul Rousseau married Janine Ducharme on April 5, 1952. They had five children: Johanne, Pauline, Lyse, Marie and Michele.