Sir John Ormsby Vandeleur (1763 – 1 November 1849) commanded a brigade of British cavalry at the Battle of Waterloo. His career in the British army began in 1781 as an ensign in an infantry regiment. He exchanged into a cavalry regiment in 1792 and served in the War of the First Coalition. In 1802 he went to India and fought in the Second Anglo-Maratha War as an acting cavalry brigadier. He returned from India in 1806 and was promoted to major general in 1811 in Portugal. He led an infantry brigade in the famous Light Division at Ciudad Rodrigo, Salamanca, San Millan, and Vitoria. Vandeleur commanded a cavalry brigade at the Nive in 1813 and was knighted in early 1815. After Waterloo he was colonel-in-chief of two cavalry regiments in succession and he was promoted to full General in 1838.