James Johnston (British Army officer, died 1795)

James Johnston (21 May 1721 – 26 November 1795) was a general of the British Army, colonel of the Royal Horse Guards (the Blues) and colonel of the Scots Greys.

He was the only surviving son of James Johnston (Secretary of State) and his wife, Lucy née Claxton. Johnston lived at Overstone, Northamptonshire and in retirement at Weston House near Bath and with a house in St James's Place, Middlesex.

Johnston was first commissioned into the Royal Horse Guards and was present with the regiment at the Battle of Dettingen in 1743 and the Battle of Fontenoy in 1745. He became a major in the regiment on 29 November 1750, was promoted to lieutenant-colonel of the Royal Horse Guards on 17 December 1754 and commanded the regiment in Germany in several engagements during the Seven Years' War.

Desperately wounded at the battle of Minden in 1759 he was promoted to full colonel of Horse, Royal Horse Guards 9 March 1762, (the same day as his 'Irish' cousin was gazetted colonel of Dragoons) and appointed an aide-de-camp to King George III.

Promoted to major-general on 30 April 1770 on 2 May 1775 he received the additional appointment of colonel of the 11th Regiment of Dragoons in place of the marquess of Lothian and was further promoted to lieutenant-general on 29 August 1777. On 2 April 1778 he was removed from his colonelcy of Royal Horse Guards and a fortnight later appointed colonel of the 6th Regiment of Dragoons. In succession to George Preston, his sister's husband, he was made colonel of the Scots Greys on 4 February 1785, a post he held until his death. On 25 October 1793 he was promoted general.

Johnston married twice. His first wife (married 2 March 1747) and mother of his children was Charlotte daughter of George Montagu first earl of Halifax and Mary Lumley. Charlotte died in childbirth 28 April 1762 but she was survived by at least three sons and three daughters. Johnston then married his cousin Frances née Carter, widow of Philip Twysden Bishop of Raphoe and mother of Frances Villiers, countess of Jersey.