Auguste Frédéric Louis Viesse de Marmont, duc de Raguse (French pronunciation: [oɡyst fʁedeʁik lwi vjɛs də maʁmɔ̃]; 20 July 1774 – 22 March 1852) was a French general and nobleman who rose to the rank of Marshal of the Empire and was awarded the title Duke of Ragusa (French: duc de Raguse). In the Peninsular War Marmont succeeded the disgraced André Masséna in the command of the French army in northern Spain, but lost decisively at the Battle of Salamanca as France ultimately lost the war in Spain.

At the close of the War of the Sixth Coalition, Marmont went over to the Restoration and remained loyal to the Bourbons through the Hundred Days. This gave Marmont a reputation as a traitor among the remaining Bonapartists, and in French society more broadly. He led the royalist Paris garrison during the July Revolution in 1830, but his efforts proved incapable of quelling the revolution, leading King Charles X to accuse Marmont of betraying the Bourbons as he had betrayed the Bonapartes.

Marmont departed France with Charles's entourage and never returned to France. Spending his exile mostly in Vienna and other lands of the Austrian Empire, he died in Venice in 1852.

Marmont was born at Châtillon-sur-Seine, the son of an ex-officer in the army who belonged to the petite noblesse and adopted the principles of the Revolution. His love of soldiering soon showed itself, and his father took him to Dijon to learn mathematics before entering the artillery. There, he made the acquaintance of Napoleon Bonaparte, which he renewed after obtaining his commission when he served in Toulon.

The acquaintance ripened into intimacy; Marmont became General Bonaparte's aide-de-camp, remained with him during his disgrace and accompanied him to Italy and Egypt, winning distinction and promotion to general of brigade. In 1799, he returned to Europe with his chief. He was present at the coup d'état of the 18th Brumaire and organized the artillery for the expedition to Italy, which he commanded with great effect at Marengo. For this, he was at once made general of division. In 1801, he became inspector-general of artillery, and in 1804, grand officer of the Legion of Honour. However, he was greatly disappointed at being omitted from the list of officers who were made marshals.

In 1805, he received the command of a corps, with which he did good service at Ulm. He was then directed to take possession of Dalmatia with his army and occupied the Republic of Ragusa. For the next five years, he was military and civil governor of Dalmatia, and traces of his beneficent régime still survive both in great public works and in the memories of the people. In 1808, he was made Duke of Ragusa.

In the War of the Fifth Coalition, he defeated an Austrian holding force in the Dalmatian Campaign of May 1809 and captured the opposing commander. Breaking out of Dalmatia, he reached Ljubljana (Laibach) in early June. After he defeated Ignaz Gyulai's corps in the Battle of Graz, Napoleon summoned the XI Corps to Vienna. Marmont arrived in time to fight in the Battle of Wagram on 5 and 6 July. In the subsequent pursuit of Archduke Charles, Marmont's corps was in a compromising position and was rescued only by the arrival of Napoleon with heavy reinforcements. Napoleon made him a Marshal of the Empire, though he said, "Between ourselves, you have not done enough to justify entirely my choice." Of the three marshals created after Wagram, the French soldiers said,

MacDonald is France's choice
Oudinot is the army's choice
Marmont is friendship's choice.