César-François Cassini de Thury (June 17, 1714 – September 4, 1784) was a French astronomer, son of Jacques Cassini.
Cassini de Thury was born at the Paris Observatory. He succeeded to his father’s official employments in 1756, continued the hereditary surveying operations, and began in 1744 the construction of a great topographical map of France. The post of director of the Paris observatory was created for his benefit in 1771, when the establishment ceased to be a dependency of the French Academy of Sciences.
His chief works were: La méridienne de l’Observatoire Royal de Paris (1744), Description géometrique de la terre (1775), and Description géometrique de la France (1784).
