Courtemanche was called to the Quebec bar in 1947 and practised law in Mont-Laurier and Montreal.
However, the election brought the Progressive Conservatives to power under John Diefenbaker with a minority government and Courtemanche rejoined the party within weeks of its election victory and was appointed Deputy Speaker of the House of Commons.
[3] Diefenbaker elevated Courtemanche to his Cabinet as Secretary of State for Canada following the 1958 federal election that returned the Tories with a majority government.
On January 20, 1960, Courtemanche resigned from Cabinet, reportedly for health reasons,[4] and was appointed to the Senate.
[7] Ultimately, Courtemanche resigned his Senate seat on December 22, 1961, less than two years into his appointment, after an investigation into his activities found him "unworthy" of public office.