François de Franquetot de Coigny (March 16, 1670 – December 18, 1759) was a Marshal of France, Count, and from 1747, the Duke of Coigny.
He was born in the Coigny château near Coutances, Normandy as son of Robert-Jean de Coigny, and Marie-Françoise de Matignon. His uncle was Charles-Auguste de Goyon-Matignon, Marshal of France and his nephew Jacques I, Prince of Monaco. Like his father he pursued a military career. He became brigadier in 1702, Maréchal de camp in 1703 and lieutenant general in 1709.
His most notable victories were at San Pietro and Guastalla, which he won in 1734 together with Marshal de Broglie against the Austrians in the War of Polish Succession. He was made a Marshal of France in 1734. In the War of the Austrian Succession he replaced Marshal de Broglie in 1743 to defend the French positions on the Rhine.
He married Henriette de Montbourcher du Bordage on December 4, 1699; they had three children:
His grandson was François-Henri de Franquetot de Coigny, also a Marshal of France.