Yves-André Rocard (22 May 1903, Vannes – 16 March 1992, Paris) was a French physicist who helped develop the atomic bomb for France.

After obtaining a double doctorate in mathematics (1927) and physics (1928) he was awarded the professorship in electronic physics at the École normale supérieure in Paris.

As a member of a Resistance group during the Second World War he flew to the UK in a small plane as part of a dangerous mission, and was able to provide British intelligence with invaluable information. There he met up with Charles de Gaulle who named him Director of Research in the Forces navales françaises libres (the Navy of Free France). He became particularly interested in the detection of solar radio emissions by British Radar, which were causing military problems by jamming detection during periods of high emission, and was able to create a new radio navigational beam station.

As research director Rocard followed the French troops entering Germany. He succeeded in finding German specialists, e.g. in infrared and wireless Pathfinding and engaged them to serve in France. As for the group of nuclear physicists around Werner Heisenberg and Otto Hahn he did not succeed because Samuel Abraham Goudsmit arrived ar Hechingen earlier. At Freiburg (then also French zone) Rocard protected the solar observatory and founded a French navy-owned ionospheric prediction service with Karl Rawer as scientific director.

Returned to France after the war Rocard he took up his function as head of the physics department at the ENS. Whilst there he founded a radio observatory, having obtained two German "Wurzburg" Radar mirrors from the war.

From 1947 he became scientific advisor to the French military on the subject of atomic energy, eventually taking over from Frédéric Joliot-Curie after his dismissal. In 1951, he became scientific head of the programme that eventually led to the development of nuclear arms, and is often known as the father of the French A-Bomb and H-bomb.

Later in his career he studied subjects ranging from semiconductors to seismology. Eventually his professional reputation became tarnished by his increased research in less conventional subjects such as biomagnetism, dowsing and UFOs.

He was awarded the British CBE (1946), and the French Legion of Honour and Order of Merit.

He is the father of Michel Rocard, prime minister of France between 1988 and 1991.

On his death in 1992, Yves Rocard was interred in the Cimetière du Montparnasse in Paris.