François-Emmanuel Guignard, comte de Saint-Priest (12 March 1735 – 26 February 1821), was a French politician and diplomat during the Ancien Régime and French Revolution.
Born in Grenoble, he was admitted as a chevalier to the Order of Malta at five years of age, and at fifteen entered the army. He left active service in 1763 with the rank of colonel, and for the next four years represented the court of France in Portugal.
Saint-Priest was sent as an ambassador in 1768 to the Ottoman Empire, where he remained (with the exception of one short interval) until 1785. There, he married Wilhelmina von Ludolf, the daughter of the ambassador of the Kingdom of Naples to the Sublime Porte. His Mémoires sur l'ambassade de France en Turquie et le commerce des Français dans le Levant, prepared during a return visit to France, were only published in 1877, when they were edited by Charles Schefer. Besides these, he wrote an Examen des assemblés provinciales (1787).
In 1788, after a few months spent at the court of The Hague, he joined the ministry of Jacques Necker as a minister without portfolio. He was one of three liberals dismissed from their posts when the conservative intrigues of the comte d'Artois (the king's youngest brother) and the duchesse de Polignac reached a climax during the second week of July 1789. That success, however, ended with the storming of the Bastille. In Necker's subsequent second cabinet, St.-Priest was reinstated as the secrétaire d'état of the royal household, the Maison du Roi. Later, in August 1790, he was also named by King Louis XVI as the Ministre de l'Intérieur.