Gérard Paul Deshayes (May 13, 1795 – June 9, 1875) was a French geologist and conchologist.He was born in Nancy, his father at that time being professor of experimental physics in the École Centrale of the département MeurtheHe studied medicine in Strasbourg, and afterwards took the degree of bachelier ès lettres in Paris in 1821; but he abandoned the medical profession in order to devote himself to natural history.