He was appointed to the Senate in 1984 by Prime Minister Trudeau.  In 1985, he was appointed as a visiting scholar in the Institute of Canadian Studies at Carleton University and over the next five years, delivered a number of guest lectures at various Canadian universities.

He was elected by the Senate as Chairman of the Standing Committee on Internal Economy, Budgets and Administration in 1988, at the beginning of the first session of the 34th Parliament.  He also sat on the Foreign Affairs Committee and on the Sub-Committee on Security and National Defence, and was a member of the Canada-France Parliamentary Association and the International Association of French-speaking Parliamentarians.  

Mr. LeBlanc's work in the Senate included a great deal of international activities and considerable work on the regulation of the pharmaceutical industry in Canada.  He was appointed Speaker on December 7, 1993.