The only son of Jules Jeanneney (a deputy in the French National Assembly, president of the French Senate, and Minister of State in Charles de Gaulle's post-WWII provisional government), Jean-Marcel Jeanneney graduated in economics from the Paris Institute of Political Studies (better known as Sciences Po). He has taught at universities in Dijon and Grenoble in the late 1930s.
In 1942, Jean-Marcel Jeanneney's son Jean-Noël Jeanneney, another important figure in French politics and education, was born.
He was his father's Chief of Staff during the provisional government (1944–1946). In 1958, he was appointed by Jacques Rueff to the Rueff-Pinay committee, a group of experts on economic reform whose ultimate product, the Rueff-Pinay plan, lowered French tariffs, returned the French franc to full convertibility after re-evaluating it, and reformed financial markets.
He was Minister of Industry in the Michel Debré government from 1959 to 1962, ending when he was appointed French ambassador and high commissioner to Algeria. He held this post for six months, immediately after Algeria became independent from France. He served then on a number of government committees between 1963 and 1966, and was Minister for Social Affairs from 1966 to 1968. Jeanneney was elected in 1968 to the National Assembly as a deputy for Isère, running with the UDR and defeating the incumbent Pierre Mendès-France. He resigned his seat shortly afterwards to become the Minister Responsible for Senate and Regional Government Reform for a year.
Over the years from 1965 to 1989, he also served in a number of posts in local government in Rioz.
He taught economics at the University of Paris I from 1970 to 1989, becoming a director at the French Fondation nationale des sciences politiques (National Foundation for Political Science). He founded the Observatoire Français des Conjonctures Economiques (French Institute for the Study of Economic Conditions) in 1981 and was its president until 1989.