Antoine de Chézy (1 September 1718, in Châlons-en-Champagne – 5 October 1798, Paris) was a French hydraulics engineer. He is known for the Chézy formula, which concerned the velocity of pipe flow,[1] and in modified form he used it for open channel flow as well.[2] He died in 1798 after being director of the École nationale des ponts et chaussées for less than a year.[3] His son was the orientalist Antoine-Léonard de Chézy.