The III Cavalry Corps of the Grande Armée was a French military unit that existed during the Napoleonic Wars. The corps was created in 1812 and reconstituted in 1813 and 1815. Emperor Napoleon Bonaparte first mobilized the corps for the invasion of Russia. Commanded by General Emmanuel de Grouchy, two divisions of the corps fought at Borodino, Tarutino, and Vyazma. A third division fought at the First and Second battles of Polotsk and the Berezina. During the War of the Sixth Coalition in 1813, General Jean-Toussaint Arrighi de Casanova led the corps at Großbeeren, Dennewitz, Leipzig, and Hanau.

Emmanuel de Grouchy, marquis de Grouchy was a French military leader who served during the French Revolutionary Wars and the Napoleonic Wars. He was the last Marshal of the Empire to be created by Napoleon, and is best known for his actions during the Waterloo campaign.