Colonel Sir William Douglas (c. 1778 – 25 August 1818) K.C.B., was a British Army officer during the Napoleonic Wars.
[5] He served on the Hanover expedition in 1805 and fought in the Peninsular War from August 1808 to June 1809.
While in theatre he was promoted to Lieutenant-Colonel of 91st Foot on 25 November 1808 and commanded the 1st Battalion from 1808 to 1818.
He served in the Walcheren expedition of 1809; again in Iberia and then France under Wellington from January 1813 to April 1814.
[5] He served in Waterloo Campaign of 1815, during which he led one of the columns that stormed Cambray on 24 June 1815.