Rocard served as prime minister for three years from mid-1988 under Francois Mitterrand, two-term Socialist president who led the country from 1981 to 1995.
Mitterrand appointed Rocard to succeed future centre right president Jacques Chirac after a period of unprecedented left-right "cohabitation".
Born on August 23, 1930 in the Parisian suburb of Courbevoie, Rocard attended the elite National School of Administration ENA and carved out a high-flying political career in a revamped and modernised Socialist Party under Mitterrand.
Rocard, noted for his pro-European stance, died in a Paris hospital, said his son Francis Rocard, an astrophysicist.
President Francois Hollande paid tribute to a man he called "a great figure of the Republic and of the Left."
Current Prime Minister Manuel Valls spoke of his "great sadness" at the loss of a "visionary statesman."
Rocard became leader of the then United Socialist Party in 1967 as the French Left battled for unity between traditionalists and modernisers and two years later stood for the presidency.
But he obtained just 3.5 percent to exit in the first round beaten by two hard Left fellow candidates who also fell by the wayside as conservative Georges Pompidou triumphed two months after the resignation of Charles De Gaulle.
Rocard served several terms as a lawmaker for the Yvelines region on the outskirts of Paris and 17 years as mayor of the town of Conflans-Sainte-Honorine.
In 1974, he joined Mitterrand's newly-founded Socialist Party and soon became a vocal critic of the traditional left.
He decided not to stand in Mitterrand's way as the latter successfully won a second term in 1988, after which he is appointed premier.
Rocard was in the post for three years before being "fired" as he saw it.
While in the top government job, Rocard signed a landmark auto-determination agreement ending unrest in the French Pacific Ocean archipelago of New Caledonia.