William Thornhill (1768 - 9 December 1851) was a British Army officer of the Peninsular War and the Waterloo Campaign.
Born in Derbyshire as the second son of Bache Thornhill of Stanton Hall,[1][2] he became a Lieutenant in the 23rd Regiment of Foot on 28 February 1800 before rising to Captain on 5 May 1804, both whilst serving in the Peninsula.
[3][1] However, he was disgraced in March that year when he failed to prevent an incursion of brigands at Villeneuve, being captured in the process but escaping.
[3] An 1821 oil sketch of him for Jan Willem Pieneman's The Battle of Waterloo was acquired by the Duke of Wellington and is now at Apsley House.
[6] He later died in Dorset[1] and is commemorated alongside the Duke of Wellington on the Andle stone on Stanton Moor in Derbyshire.