François-Julien du Dresnay des Roches (28 January 1719, Saint-Pol-de-Léon — Kerlaudy, 12 August 1786) was a French Navy officer and colonial administrator of the 18th century.
Desroches was born third son to Marie Gabrielle Thérèse le Jar de Clesmear and to Joseph Marie du Dresnay des Roches, a Captain in the French Navy.
He was promoted to Ensign in 1741, and to aide-major in 1751..He was knighted in the Order of Saint Louis in 1747.
He was promoted to Captain in 1757, and given command of Dragon in 1761, part of the squadron under Blénac.
In 1780, Desroches married Marie Émilie de Caumont Gauville.