Emmanuel, count of Mensdorff-Pouilly (24 January 1777 – 28 June 1852) was an army officer in the Imperial and Royal Army of the Austrian Empire, and vice-governor of Mainz.
The Mensdorff-Pouilly family originated from the barony of Pouilly in Stenay on the river Meuse in Lorraine. Albert-Louis, Baron de Pouilly et de Chaffour, Comte de Roussy (1731–1795) and his wife Marie Antoinette (1746–1800) emigrated together with their children during the French revolution. Their sons, Albert (1775–1799) and Emmanuel (baptised at Nancy on 24 January 1777), took the name Mensdorff from a community in the county of Roussy, Luxembourg.
The brothers entered military service against revolutionary and Napoleonic France, and Albert was killed in battle. During the War of the Fifth Coalition Emmanuel was decorated with the Military Order of Maria Theresa. In 1810 he was given command of the Galician regiment of ulans „Erzherzog Carl“ Nr. 3. Serving as a commander of a cavalry brigade in Bohemia, Mensdorff-Pouilly became commander of the Fortress of Mainz. From 1829 to 1834 Mensdorff-Pouilly also served as vice-governor of Mainz. After again having served in Bohemia, in 1840 Mensdorff-Pouilly became vice-president of the Hofkriegsrat. In 1848 he retired from the army with the rank of feldmarschallleutnant. During the Revolution of 1848 Mensdorff-Pouilly was sent as a commissioner to Prague, where he tried in vain to impress on the Prince of Windisch-Grätz the necessity to avoid bloodshed.