Louis Pierre Aimé, baron Chastel (French pronunciation: [lwi pjɛʁ ɛme ʃastɛl]; 29 April 1774, in Veigy, near Carouge, Savoy – 26 September 1826, in Geneva) was a French officer in the Napoleonic Wars, who rose to lieutenant general of cavalry.
He was made major en second (Lieutenant Colonel) of the mounted grenadiers of the Imperial Guard, in 1803, following Austerlitz, where his bravery got him recognised by Napoleon.
He then fought in Spain during the Peninsular War, including Burgos, becoming an officer of the Légion d'honneur in November 1808.
During the return of Napoleon to power, Chastel served as commanding officer of 10th Cavalry Division together with Major General Jean Baptiste Alexandre Strolz' 9th Cavalry Division in General Exelman's II Corps of the armée du Nord.
On 1 July 1815, Napoleon's Grande Armée fought its last battle in Rocquencourt and Le Chesnay, when Strolz' 2nd Cavalry Division, their rear covered by Chastel, together with three battalions of the 44th Line Infantry Regiment, and a half battalion of the Sèvres National Guard hunted down Oberstleutnant Eston von Sohr's Prussian cavalry brigade, wrecking the 3rd Brandenburg and 5th Pommeranian Hussar Regiments.